EP0059901B2 - Microprocessor-controlled device for a rotatable, extendable ladder or similar lifting arm - Google Patents

Abstract

1. A control device for a rotatable, extendable ladder or similar lifting arm including at least a control for raising and lowering, a control for extension and retraction and a control for rotation to the manual selection instruments for the desired movements, the activators of raising and lowering, of extension and retraction, and of rotation, said selection instruments being adapted to apply electric signals to a microprocessor control signal reader, the said microprocessor containing a memory : the maximal reach to not exceed a function of diverse selectable and predetermined parameters of use of the ladder ; a sequence of cyclic calculations of the actual reach from information given by sensors of vertical angle and extension length ; a cyclic sequence of comparison of the actual calculated reach with the maximal reach corresponding to pre-defined conditions of use and authorizing or not the movement requested ; characterized in that the said electric signals are representative of the direction of the command and the desired speed of execution of the desired movements and that the said microprocessor contains in its memory a deceleration law, for the movements of lowering and extension at least, in the predetermined terminal zones of the evolution of these movements corresponding to a certain approach to the predetermined maximal reach for the circumstances ; and cyclic comparison sequence for this approach of the control speed shown with the speed derived from the said law for each movement considered, destined to impose the said law when the control speed shown is excessive, by furnishing to the outputs of the microprocessor controlling these movements the signals representative of the control speed shown or automatically modified as a function of the said law ; said outputs being connected to the instruments of electric control proportional to the activation of the activators of the movements considered.

Description

The present invention relates to a control device including the control and the safety of the movements of a ladder, such as for example a rescue and fire fighting ladder, or of a similar lifting arm mounted on a vehicle.

Analog electronic control devices are known based on the following principle: an index symbolizes on a diagram the position of the end of the elevator and allows, thanks to a suitable coordinate axis system, the reading of the functional parameters.

This index comprises a conductive part of the electric current which, during the movement of the index, switches electrically with the different zones of the diagram, themselves conductive and generally produced in the form of printed circuits. Switching with these zones produces the lighting or extinction of warning lights and possibly the automatic stop of movements when these become dangerous, in particular for the stability of the carrier vehicle.

These devices are generally associated with an analog electromechanical or electronic logic system, which generates from information received from different sensors and the moving index, orders causing the change of state of indicators, the triggering of alarm (s) sound (s) or devices acting on the execution of movements.

The increase in the number of operating parameters due in particular to the use of vehicle stabilization systems with axes of variable support points, as well as the quest for greater precision in the measurement, processing and indication of the operating parameters makes it difficult to produce simple and reliable analog systems.

English patent application 2 050 294 relates generally to a steerable crane control involving a microprocessor, sensors of certain operating parameters, and comparisons with a table of limit data stored in memory, in order to trigger before exceeding these, an alarm and / or safety stop command for the crane movement. This must be regarded as a state of the art to which also relates the German patent application 2,836,337 as well as the European patent application 0 008 210.

The English patent application 2 050 294 relates essentially (rev. 1) to a particular use of operating parameter to determine by calculation the actual working state of the boom (length and bending). The safety stop phase is provided for by a simple movement cut-off by relay (see description and claim 4).

European patent application 0 008 210 relates essentially to an arrangement of optical encoders for processing the picked-up operating parameters chosen with a view to their processing and comparison with limit data.

German patent application 2 836 337 relates to the joint use of two chains of different security parameters (double security) tested separately by a microcomputer intended to give only an alarm in the event of a fault indicated by one of the monitoring chains , and to continue the operation of the crane as long as the other chain does not in turn give contrary indication.

German patent application no. 20 33 469 relates to the control of a scale on the basis of a measurement of the real torque and of a comparison of this real torque with a predetermined maximum torque.

In none of these applications is it provided, in combination with a microprocessor reader of electrical signals representative of the direction and speed of execution of the desired movements, arrangements making it possible to obtain an automatic speed deceleration when approaching the corresponding limit of use.

As claimed, the control device of the invention for a deployable orientable ladder, or similar lifting arm, provided with an articulated platform suitable for transporting one or more people, comprises at least one raising or lowering control, a deployment and folding control and a pivoting control with members for manual selection of the desired movements, straightening and lowering, deployment and folding, and pivoting actuators, said selection members being adapted to supply representative electrical signals direction of control and the desired speed of execution of the desired movements. According to the invention, the device comprises a microprocessor reader of the control signals receiving said electrical signals. Said microprocessor comprises in memory: the maximum ranges not to be exceeded as a function of various selectable and predetermined parameters for bringing the scale into service, including choices of predetermined loads and predetermined scale orientations; a sequence of cyclic calculation of the actual range from information given by sensors for measuring the angle of training and the length deployed; a cyclic comparison sequence of the real range calculated with the maximum range corresponding to the predefined implementation conditions and whether or not authorizing the requested movement.

Said microprocessor further includes in memory a law for decelerating the lowering and deployment movements at least, in predetermined terminal zones of evolution of these movements corresponding to a certain approach to the maximum predetermined range of use corresponding to the case of 'the use of the scale, taking into account the choice of load made by the user, said end zones being limited by said predetermined maximum operating range and being constantly recalculated by the microprocessor during movement.

The microprocessor also includes in memory a cyclic comparison sequence, in this approach, of the displayed control speed with the speed derived from said law for each movement considered, intended to impose said law when the displayed control speed is excessive, by providing at the outputs of the microprocessor controlling these movements of the signals representative of the displayed control speed or automatically modified according to said law to reach the maximum predetermined range at zero speed; said outputs being connected to proportional electrical control members for activating the actuators of the movements considered.

In addition, such a microprocessor control also makes it possible to limit the acceleration on switching on and off in response to orders for voluntary commands to switch on or off, by means of predetermined laws stored in memory.

Such a command also lends itself to the digital display of the operating parameters with as high a precision as desired, whether in particular the current parameters or operating limits.

Reaching the operating limit marked by the abovementioned automatic stopping process can also be advantageously accompanied by assistance with subsequent piloting by sending a spoken message indicating to the pilot the solution or solutions remaining at his disposal.

Such a microprocessor control also has the advantage of being easily adaptable to all options of equipment of the equipment and of changes of the limits for which it suffices to modify the data taken into memory.

It is known that a microprocessor also lends itself to the easy establishment of a self-diagnostic program making it possible in particular to identify defective sensors if necessary.

In addition, in the case of equipment with the usual platform articulated at the upper end of the ladder, the microprocessor also allows the command and automatic control of the horizontal alignment of the platform floor according to the angle of the ladder.

• la figure 1 est une vue schématique d'une telle échelle sur véhicule indicative de ses paramètres de fonctionnement ;
• la figure 2 est une vue de côté de l'ensemble de l'échelle seule sur son véhicule ;
• la figure 3 est un diagramme des limites d'utilisation de l'échelle en fonction des différents paramètres de fonctionnement ;
• la figure 4 est un schéma général d'ensemble des entrées et sorties du microprocesseur ;
• la figure 5 représente la constitution générale du système électronique à microprocesseur ;
• la figure 6 représente un exemple de réalisation de tableau d'affichage ;
• la figure 7 est un schéma d'ensemble du système hydraulique de commande des divers mouvements de l'échelle ;
• la figure 8 est l'organigramme général des opérations exécutées par le microprocesseur ;
• la figure 9 est un organigramme détaillé des divers calculs effectués par le microprocesseur, de leur mémorisation et des affichages en découlant ;
• la figure 10 est un organigramme des divers affichages et signalisations d'information de l'utilisateur ;
• la figure 11 est un organigramme relatif aux diverses conditions d'utilisation et de portée de l'échelle ;
• la figure 12 est l'organigramme schématique de l'opération de contrôle d'un mouvement (mouvement d'abaissement pris en exemple) ;
• la figure 13 est l'organigramme de principe du ralentissement automatique des mouvements avant arrêt automatique ;
• la figure 14 est un diagramme de vitesse en fonction de l'espace pour l'un des mouvements de l'échelle ;
• les figures 15 et 16 sont des vues illustratives complémentaires d'un mode de ralentissement automatique progressif à plusieurs paliers contrôlé par le microprocesseur pour le mouvement de développement de l'échelle ;
• les figures 17 et 18 sont des vues illustratives complémentaires concernant le ralentissement automatique progressif du mouvement d'abaissement de l'échelle ;
• les figures 19 et 20 sont des vues illustratives complémentaires se rapportant au ralentissement automatique progressif du mouvement de pivotement de l'échelle ;
• la figure 21 est l'organigramme de principe de la commande automatique de mise à l'horizontale de la plate-forme ;
• la figure 22 est un schéma de principe du système d'émission de messages parlés.

An embodiment of a microprocessor control device for a deployable orientable ladder is furthermore described below by way of illustrative example of the invention and with reference to the appended drawing, in which:

• Figure 1 is a schematic view of such a scale on the vehicle indicative of its operating parameters;
• Figure 2 is a side view of the entire ladder alone on his vehicle;
• FIG. 3 is a diagram of the limits of use of the scale as a function of the different operating parameters;
• FIG. 4 is a general overall diagram of the inputs and outputs of the microprocessor;
• FIG. 5 represents the general constitution of the electronic microprocessor system;
• FIG. 6 represents an exemplary embodiment of a display board;
• FIG. 7 is an overall diagram of the hydraulic system for controlling the various movements of the ladder;
• FIG. 8 is the general flowchart of the operations executed by the microprocessor;
• FIG. 9 is a detailed flow diagram of the various calculations carried out by the microprocessor, of their storage and of the displays resulting therefrom;
• FIG. 10 is a flow diagram of the various displays and indications of user information;
• FIG. 11 is a flowchart relating to the various conditions of use and scope of the scale;
• FIG. 12 is the schematic flow diagram of the operation for controlling a movement (lowering movement taken as an example);
• FIG. 13 is the principle flow diagram of the automatic slowing down of the movements before automatic stopping;
• FIG. 14 is a diagram of speed as a function of space for one of the movements of the scale;
• FIGS. 15 and 16 are complementary illustrative views of a progressive automatic slowdown mode with several stages controlled by the microprocessor for the development movement of the ladder;
• FIGS. 17 and 18 are additional illustrative views concerning the progressive automatic slowing down of the ladder lowering movement;
• FIGS. 19 and 20 are additional illustrative views relating to the progressive automatic deceleration of the pivoting movement of the ladder;
• FIG. 21 is the flow diagram of the principle of the automatic control for horizontal adjustment of the platform;
• FIG. 22 is a block diagram of the system for transmitting spoken messages.

• ― d'un châssis-cabine 1 à quatre vérins de calage 2 qui assurent la stabilité du châssis pendant l'utilisation de l'échelle. Chacun des vérins est monté sur une poutre support télescopique 3 qui permet d'ajuster le polygone d'appui à la place disponible autour du véhicule (distance d variable) ;
• ― d'une tourelle d'orientation 4 qui peut pivoter par rapport au châssis (angle θ). Cette tourelle comporte en outre une partie 5 articulée autour d'un axe horizontal 5a en vue de maintenir l'axe des éléments d'échelle dans un plan vertical passant par cet axe même lorsque le véhicule est incliné (dispositif de correction de dévers angle δ) ;
• ― d'un support d'échelle 6 appelé berceau articulé autour d'un axe horizontal 6a et qui permet de faire varier l'angle de dressage α de l'échelle de - 15° à + 75° ;
• ― de quatre plans d'échelle télescopiques 7, 8, 9, 10 à développement simultané ;
• ― d'une plate-forme de sauvetage amovible 11 articulée en bout du plan d'échelle 10 suivant un axe 12 afin de pouvoir conserver l'horizontalité de son plancher pendant les mouvements de dressage ou d'abaissement (angle β).

The vehicle ladder shown in Figures 1 and 2 consists of:

• - a chassis-cab 1 with four wedging cylinders 2 which ensure the stability of the chassis during use of the ladder. Each of the jacks is mounted on a telescopic support beam 3 which makes it possible to adjust the support polygon to the space available around the vehicle (distance d variable);
• - an orientation turret 4 which can pivot relative to the chassis (angle θ). This turret further comprises a part 5 articulated around a horizontal axis 5a in order to maintain the axis of the ladder elements in a vertical plane passing through this axis even when the vehicle is tilted (tilt angle correction device δ);
• - a ladder support 6 called a cradle articulated around a horizontal axis 6a and which makes it possible to vary the dressing angle α of the scale from - 15 ° to + 75 °;
• - four telescopic ladder planes 7, 8, 9, 10 for simultaneous development;
• - a removable rescue platform 11 articulated at the end of the ladder plane 10 along an axis 12 in order to be able to maintain the horizontality of its floor during the dressing or lowering movements (angle β).

A scale movement control and safety system aims to provide the user with the value of the operating parameters such as the angle of dressing α, the developed length L, the maximum possible load at the end of the ladder, the height reached H, the range P ... to alert the user and possibly stop the movements when they become dangerous, in particular in the event of an impact with an obstacle or in the event of being reached vehicle stability limits.

• a) Extrémité de l'échelle non appuyée ; poutres 3 rentrées, orientation échelle défavorable (limites indiquées en trait plein) ;
  • a1) trois hommes plus la plate-forme de sauvetage (portée P1) ;
  • a2) trois hommes à l'extrémité, sans plate-forme, ou deux hommes plus plate-forme (portée P4) ;
  • a3) deux hommes à l'extrémité, sans plate-forme, ou un homme plus plate-forme (portée P7) ;
  • a4) un homme à l'extrémité, sans plate-forme (portée P10) ;
• b) poutres 3 demi-sorties, ces limites deviennent : a'1, a'2, a'3, a'4 (en trait mixte) auxquelles correspondent les portées P2, P5, P8 et P11 ;
• c) poutres 3 sorties ou orientation échelle voisine de l'axe du véhicule, ces limites deviennent a''1, a''2, a''3, a''4 (en trait pointillé) auxquelles correspondent les portées P3, P6, P9, P12 ;
• d) extrémité de l'échelle en appui, deux hommes par plan d'échelle (b, b', b'', selon sortie poutres) auxquelles correspondent les portées P13, P14, P15.

Figure 3 gives as an example the limit use diagrams of the scale corresponding to the minimum stability allowed in the following use cases:

• a) End of the ladder not supported; 3 re-entrant beams, unfavorable scale orientation (limits indicated in solid lines);
  • a1) three men plus the rescue platform (range P1);
  • a2) three men at the end, without platform, or two men more platform (reach P4);
  • a3) two men at the end, without platform, or one man with a platform (litter P7);
  • a4) a man at the end, without platform (reach P10);
• b) beams 3 half-outlets, these limits become: a'1, a'2, a'3, a'4 (in phantom) to which the spans P2, P5, P8 and P11 correspond;
• c) 3-outlet beams or scale orientation close to the vehicle axis, these limits become a''1, a''2, a''3, a''4 (in dotted lines) to which the spans P3, P6 correspond , P9, P12;
• d) end of the ladder in support, two men per ladder plane (b, b ', b'', depending on beam exit) to which the spans P13, P14, P15 correspond.

This figure 3 symbolizes the usage diagrams corresponding to three possible positions of the support cylinders, but a continuous variation of the diagram can be envisaged.

Depending on the position of the support beams of the timing cylinders and the angle of orientation of the ladder relative to the chassis, a limit of use of the ladder, before any risk of overturning, is defined experimentally for each load case.

The different limits are stored in the control system.

During the movements of the ladder, the control system compares the position of the ladder to each of the limits and lights up an indicator which corresponds to the possibility of maximum load. Automatic deployment, lowering and possibly pivoting movements are stopped when the ladder fitted with its rescue platform reaches the limit corresponding to the load case a1, a2, and a3, or when the ladder without rescue platform reaches the limit corresponding to a4, or the limits going from a'1 to a'4 or from a''1 to a''4 depending on the position of the beams 3.

Continuation of movements after these limits to reach limits b, b ', b' '(ranges P13, P14, P15) can only be done if the operator actuates a contactor "ladder in support". A new automatic stop of the deployment, lowering and possibly pivoting movements occurs when the limits b, b 'or b' 'are reached.

Each time the load limit is changed, an audible device is activated to attract the attention of the user.

When the rescue platform is used, a sensor signals its presence.

Switches allow you to select the limits: two men plus platform, one man plus platform. Before reaching the usage limit corresponding to the chosen load case, a pre-signal intervenes as well as a slowing down of the maneuvers as will be seen below.

The general principle of operation is first indicated below with reference to the overall diagram and of the microprocessor control MPU of FIG. 4.

The scale position information delivered by the various sensors is read periodically by the microprocessor and stored in memory.

The microprocessor processes this data and compares the state of the scale with the limits of use stored in permanent memory.

The movement control orders (direction and speed) given by the operator enter the microprocessor; they are validated or modified according to the result of the comparison of the state of the scale to the limits of use and then transmitted to the power control members. Simultaneously, the microprocessor generates, if necessary, the orders for controlling the automatic movement of the horizontal floor of the platform.

If it happens that the operator requests a movement which becomes dangerous for the stability of the vehicle, the microprocessor causes the automatic stop of this movement when the limit is reached, but after having achieved a progressive deceleration of the movement until the total stop and this whatever the command order given by the operator as we will see later.

• ― Deux mémoires programmables (REPROM 1 et 2) ici les 2716 de MOTOROLA. La totalité du programme est enregistré dans ces mémoires (4K octets avec possibilité d'extension).
• ― Une mémoire de travail externe (RAM) ici la 6810 de MOTOROLA. C'est dans cette mémoire que sont stockés les paramètres extérieurs et les résultats des calculs. (128 octets en plus des 128 octets du MPU. Extension possible).
• ― Des interfaces d'adaptation des entrées et sorties à codage d'adresse (PIA 1 et PIA 2) ici les 6821 de MOTOROLA.

FIG. 5 illustrates the general constitution of the electronic microprocessor system which comprises: a microprocessor (MPU) here the 6802 from MOTOROLA, which coordinates all the functions of the system and has an internal working memory (RAM) of 128 bytes.

• - Two programmable memories (REPROM 1 and 2) here the 2716 from MOTOROLA. The entire program is saved in these memories (4K bytes with possibility of extension).
• - An external working memory (RAM) here the 6810 from MOTOROLA. It is in this memory that the external parameters and the results of the calculations are stored. (128 bytes in addition to the 128 bytes of the MPU. Extension possible).
• - Adaptation interfaces for address coded inputs and outputs (PIA 1 and PIA 2) here the 6821 from MOTOROLA.

• ― BUS des DONNEES = ensemble de fils véhiculant les informations d'entrées, sorties ou mémoire.
• ― BUS des ADRESSES = ensemble de fils comportant le codage des emplacements ou destinations des informations véhiculées par le BUS des DONNEES.
• ― BUS de COMMANDE = ensemble de fils par lesquels cheminent les signaux de commande auxiliaires validant les adresses et transferts des données.

All these elements are linked together by standard BUSes.

• - DATA BUS = set of wires carrying input, output or memory information.
• - ADDRESS BUS = set of wires comprising the coding of the locations or destinations of the information conveyed by the DATA BUS.
• - CONTROL BUS = set of wires through which the auxiliary control signals validate the addresses and data transfers.

• ― Des circuits d'entrées logiques avec opérateurs de puissance (BUFFERS D'ENTREES 1, 2 et 3).
• ― Deux multiplexeurs 1 et 2 d'entrées analogiques, ici les IH 6116 de TEKELEC suivis d'un convertisseur Analogique/Numérique.
• ― Un circuit de sorties logiques pour voyants de contrôle (sorties S1 à S16).
• ― Huit décodeurs BCD à 7 segments, ici les M 04311B de MITEL, pour affichage numérique de divers paramètres (sorties S25 à S32).
• ― Des convertisseurs Numérique/Analogique pour toutes les sorties de commande proportionnelle des mouvements (S33 à S37).
• ― Un circuit de sorties logiques avec opérateurs de puissance (BUFFER DE SORTIE S17 à S19).
• ― Deux décodeurs servant de démultiplexeurs pour entrées, sorties et circuits d'affichage numérique (ici les décodeurs 74 LS 138 de MOTOROLA).

In addition, additional circuits allow adaptation of external elements (detectors, measurements and controls for inputs, contacts, indicators, digital displays and movement controls for outputs). These circuits are:

• - Logic input circuits with power operators (INPUT BUFFERS 1, 2 and 3).
• - Two multiplexers 1 and 2 of analog inputs, here the TEKELEC IH 6116 followed by an Analog / Digital converter.
• - A logic output circuit for indicator lights (outputs S1 to S16).
• - Eight 7-segment BCD decoders, here MITEL's M 04311B, for digital display of various parameters (outputs S25 to S32).
• - Digital / Analog converters for all proportional motion control outputs (S33 to S37).
• - A logic output circuit with power operators (OUTPUT BUFFER S17 to S19).
• - Two decoders serving as demultiplexers for inputs, outputs and digital display circuits (here the 74 LS 138 decoders from MOTOROLA).

The entire program allowing the command and control of the operation of the scale is saved in REPROM memory. On this same memory are recorded all the limits of use allowed according to the different scenarios that the scale can take.

• ― Entrées logiques : E1 (Alimentation électrique) ; E2 (Pression d'huile des vérins de calage) ; E3 (Echelle sur support échelle) ; E4 (Poutres télescopiques sorties côté gauche) ; ES (Poutres télescopiques sorties côté droit) ; E6 (Poutres télescopiques 1/2 sorties côté gauche) ; E7 (Poutres télescopiques 1/2 sorties côté droit) ; E8 (Réarmement microprocesseur) ; E9 (Plate-forme de sauvetage en bout d'échelle) ; E10 (Utilisation avec deux hommes dans la plate-forme) ; E11 (Utilisation avec un homme dans la plate-forme) ; E12 (Utilisation de l'échelle avec appui) ; E13 (Arrêt d'urgence - coup de poing) ; E14 (Fin de course reploiement) ; E15 (Fin de course déploiement) ; E16 (Marche/arrêt concordance automatique d'échelons) ; E17 (Capteur de concordance d'échelons) ; E18 (Capteur de choc à l'abaissement) ; E19 (Capteur de choc au déploiement) ; E20 (Capteur de choc au pivotement à droite) ; E21 (Capteur de choc au pivotement à gauche) ; E23 (Capteur d'angle de dressage où l'échelle peut heurter la cabine pendant le pivotement) ; E24 (Sécurité dévers maximal) ; E25 (Fin de course abaissement) ; E26 (Fin de course dressage) ; E27 (Début de zone de ralentissement avant fin de course abaissement) ; E28 (Début de zone de ralentissement avant fin de course dressage) ; E29 (Sécurité mise à l'horizontale de la plate-forme à l'abaissement) ; E30 (Sécurité mise à l'horizontale de la plate-forme au dressage) ; E31 (Plate-forme verrouillée en position travail) ; E32 (Plate-forme verrouillée en position route) ; E33 (Commande de retour automatique de l'échelle sur son support) ; E34 (Commande de secours sans sécurité automatique).
• ― Entrées analogiques E41 (Commande dressage/abaissement) ; E42 (Commande déploiement/reploiement) ; E43 (Commande pivotement droite/gauche) ; E44 (Mesure de l'angle de dressage α) ; E45 (Mesure de l'angle de la plate-forme par rapport à l'échelle β) ; E46 (Mesure de l'angle de pivotement θ) ; E47 (Mesure de la longueur développée L) ; E48 (réservée) ; E49 (réservée) ; E50 (Mesure de l'angle de correction de dévers δ) ; E51 (Mesure de surcharge de la structure).
• ― Sorties logiques : S1 (Voyant défaut du système électronique) ; S2 (Voyant dévers trop important) ; S3 (Voyant plate-forme avec trois hommes) ; S4 (Voyant plate-forme avec 2 hommes) ; S5 (Voyant plate-forme avec un homme) ; S6 (Voyant trois hommes sur l'échelle) ; S7 (Voyant deux hommes sur l'échelle) ; S8 (Voyant un homme sur l'échelle) ; S9 (Voyant échelle en appui) ; S10 (Voyant concordance d'échelons) ; S11 (Voyant demandant le dressage ou le reploiement) ; S12 (Voyant poutres télescopiques sorties ou échelle dans l'axe du châssis) ; S13 (Voyant poutres télescopiques 1/2 sorties) ; S14 (Voyant poutres télescopiques rentrées) ; S15 (Voyant défaut correction dévers) ; S17 (Avertisseur de changement de zone d'utilisation) ; S18 (Avertisseur signalant l'approche ou l'arrêt automatique) ; S19 (Pilotage pression d'huile de la pompe hydraulique).
• ― Sorties numériques : S25 (Affichage angle de dressage α) ; S26 (Affichage longueur développée L) ; S27 (Affichage portée) ; S28 (Affichage hauteur) ; S29 (Affichage de la longueur développable avant changement de zone d'utilisation) ; S30 (Affichage de la portée maximale avant changement de zone d'utilisation) ; S31 (Affichage de la hauteur maximale avant changement de zone d'utilisation) ; S32 (Affichage du numéro de capteur défectueux).
• ― Sorties analogiques : S33 (Commande proportionnelle dressage/abaissement) ; S34 (Commande proportionnelle développement/reploiement) ; S35 (Commande proportionnelle pivotement droite/gauche) ; S36 (Commande proportionnelle de mise à l'horizontale de la plate-forme) ; S37 (Commande proportionnelle de correction de dévers).

The various inputs and outputs taken into account here are in particular:

• - Logic inputs: E1 (Power supply); E2 (Oil pressure of the timing cylinders); E3 (Ladder on ladder support); E4 (Telescopic beams exited on the left side); ES (Telescopic beams exiting right side); E6 (1/2 extension telescopic beams left side); E7 (1/2 extension telescopic beams on right side); E8 (Microprocessor reset); E9 (End of ladder rescue platform); E10 (Use with two men in the platform); E11 (Use with a man in the platform); E12 (Use of ladder with support); E13 (Emergency stop - punch); E14 (Limit switch); E15 (Deployment limit switch); E16 (On / off automatic step matching); E17 (Scale concordance sensor); E18 (Lowering shock sensor); E19 (Deployment shock sensor); E20 (Right pivoting shock sensor); E21 (Left pivoting shock sensor); E23 (Dressing angle sensor where the ladder can hit the cabin during pivoting); E24 (Maximum cant safety); E25 (Lowering limit switch); E26 (Dressage limit switch); E27 (Start of deceleration zone before lowering limit switch); E28 (Start of slowdown zone before end of dressage race); E29 (Safety horizontally lowering the platform); E30 (Safety placed horizontally from the platform to the dressing); E31 (Platform locked in working position); E32 (Platform locked in road position); E33 (Automatic scale return command on its support); E34 (Emergency control without automatic safety).
• - Analog inputs E41 (Dressing / lowering command); E42 (Deployment / deployment control); E43 (Right / left swivel control); E44 (Measurement of the dressing angle α); E45 (Measurement of the angle of the platform with respect to the scale β); E46 (Measurement of the pivot angle θ); E47 (Measurement of the developed length L); E48 (reserved); E49 (reserved); E50 (Measurement of the slope correction angle δ); E51 (Structure overload measurement).
• - Logic outputs: S1 (Electronic system fault indicator); S2 (Overlap indicator too large); S3 (Platform light with three men); S4 (Platform light with 2 men); S5 (Seeing platform with a man); S6 (Seeing three men on the ladder); S7 (Seeing two men on the ladder); S8 (Seeing a man on the ladder); S9 (Scale indicator in support); S10 (Scale agreement indicator); S11 (Indicator requesting training or folding back); S12 (Indicator for telescopic beams extended or ladder in the axis of the chassis); S13 (1/2 exit telescopic beams indicator); S14 (Telescopic beams retracted indicator); S15 (Slope correction fault indicator); S17 (Use area change warning); S18 (Warning signaling automatic approach or stop); S19 (Hydraulic pump oil pressure control).
• - Digital outputs: S25 (Display of dressing angle α); S26 (Extended length display L); S27 (Range display); S28 (Height display); S29 (Display of the developable length before changing the area of use); S30 (Display of the maximum range before changing the area of use); S31 (Display of the maximum height before changing the area of use); S32 (Display of defective sensor number).
• - Analog outputs: S33 (Proportional raising / lowering control); S34 (Proportional development / deployment control); S35 (Proportional control pivoting right / left); S36 (Proportional control for horizontal alignment of the platform); S37 (Proportional tilt correction control).

The operating principle is as follows:

After powering up the device as a whole, the program plans to initialize the memory boxes in RAM.

The MPU via the data BUS, by exciting the corresponding addresses, allows the transfer of REPROM to RAM of the initialization parameters.

Then, the program provides for reading and storing the entries in RAM. All digital inputs E1 to E34 are present as 1 or 0 at the terminals of the input BUFFERS.

The MPU, thanks to the addresses of the input PIA 1 and BUFFER 1, reads all of the inputs E1 to E16 which must be transferred to RAM by the BUS of the data and the memory addresses.

Likewise, for inputs E17 to E32 with the input PIA 1 and BUFFER 2 and so on in series of 16 inputs.

All analog inputs E41 to E51 are present as a voltage across the terminals of analog input multiplexers.

The MPU, thanks to the addresses of the PIA 1, the multiplexer 1 and the A / D converter, reads the input E41, converted into digital and transfers by the BUS data and the address of the memory, the corresponding binary word in the RAM.

Likewise, for each of the inputs E42 to E48, and for the inputs E49 to E51 with the addresses PIA 1, multiplexer 2 and the intermediate A / D converter.

When all the external data is in RAM memory, the MPU performs the calculations necessary for the smooth running of the program by going to draw from RAM by the data BUS and addresses the previously stored data.

The results of these calculations are firstly stored in RAM via the data BUS and new addresses and secondly displayed on the control panel delimited in dashed line in Figure 5. This transfer to the panel '' display of logic indicators: beam position, alert load case ... is done via data BUS and PIA 2 addresses and the output decoder, which allows up to 16 information to be transmitted at once (S1 to S15 in this example).

The display of the training angle, developed length, span and height parameters is done via the data buses and addresses of the PIA 2, the digital display decoder, and a 7-segment decoder for each digital output. , i.e. for S25 to S32 in a row.

Then comes the verification of the operation of the ladder (with or without platform) taking into account the speed control information of the different movements, safety parameters, for issuing speed control orders for the movement of the scale, this following an order of tests defined by the flowchart that will be seen below.

When the entire program in the flowchart has been viewed and the operating or stopping orders given, the MPU returns to the start of the program.

The MPU, on each cycle, reads all the logic and analog inputs that it stores in RAM at the same addresses as before, the parameters already stored being automatically erased.

Then the MPU performs all the calculations with this new information and the elements displayed are possibly updated.

In some cases, to avoid the digits scrolling for example, certain data are only displayed every 2 seconds for example.

The MPU completes the program in a few milliseconds. This time is variable depending on the number of movements performed. In any event, each of the scale control parameters is read approximately 200 times per second.

Self-checking of the inputs is included in the programs; for example, in measurements, if two successive readings of an analog input give a large deviation, the new value is not validated and other measurements are made. If this fault persists, the MPU, by displaying the number assigned to the faulty sensor, signals this incident and possibly stops the normal operation of the scale.

Likewise, the information given by certain logic sensors is verified as a function of the measurement of an analog parameter. The reverse also exists, for example, if the logic input E23 is detected, the analog input E44 must obligatorily give a value of dressing angle less than + 6 °.

In addition, each time the MPU gives a motion command, the direction of variation of the analog measurements is checked, for example S34 + 1V = proportional command output. S34 therefore gives a positive signal. The MPU checks whether the value of the analog input E47 (Measurement of the developed length) believes, if not, as previously, the reading of the input E47 is carried out several times, and if the anomaly persists, there is display of the number assigned to the sensor E47 and the operation of the ladder.

The system thus performs a self-check and avoids giving erroneous orders in the event that it receives false information.

The microprocessor also controls the display and signaling panel which informs the user about the state of the scale and its possibilities.

• ― Position des vérins de calage par rapport au véhicule : cases 13, 14, 15 par allumage des voyants 16, 17, 18 ;
• ― Position de l'échelle : angle de dressage (case 19, afficheur numérique 20), longueur développée (case 21, afficheur 22), portée (case 23, afficheur 24), hauteur (case 25, afficheur 26) ;
• ― Possibilités maximales de l'échelle au même angle de dressage et à la même charge : longueur maximale (case 27 afficheur 28), portée maximale (case 29, afficheur 30), hauteur maximale (case 31, afficheur 32) ;
• ― Possibilités de charge de l'échelle : trois hommes dans la plate-forme (voyant 33) ; deux hommes dans la plate-forme (voyant 34) ; un homme dans la plate-forme (voyant 35) ; trois hommes à l'extrémité de l'échelle (voyant 36) deux hommes à l'extrémité de l'échelle (voyant 37) ; un homme à l'extrémité de l'échelle (voyant 38) ; huit hommes sur l'échelle en appui (voyant 39) ;
• ― Fonction particulière : concordance des échelons des différents éléments de l'échelle (case 40, voyant 41) ; défaut de fonctionnement du microprocesseur (case 42, voyant 43), nécessité de reployer ou de dresser l'échelle (case 44, voyant 45), mauvais fonctionnement d'un capteur avec affichage du numéro du capteur (case 46, afficheur numérique 47), défaut correction dévers (voyant 48) les cases 49, 50 étant ici libres avec des voyants indicateurs supplémentaires.

FIG. 6 illustrates an embodiment of the display board. The following information is given to the operator:

• - Position of the timing cylinders relative to the vehicle: boxes 13, 14, 15 by lighting of the indicator lights 16, 17, 18;
• - Position of the scale: dressing angle (box 19, digital display 20), developed length (box 21, display 22), range (box 23, display 24), height (box 25, display 26);
• - Maximum possibilities of the ladder at the same dressing angle and at the same load: maximum length (box 27 display 28), maximum range (box 29, display 30), maximum height (box 31, display 32);
• - Ladder load possibilities: three men in the platform (light 33); two men in the platform (see 34); a man in the platform (see 35); three men at the end of the scale (light 36) two men at the end of the scale (light 37); a man at the end of the ladder (see 38); eight men on the ladder in support (light 39);
• - Special function: concordance of the steps of the different elements of the scale (box 40, indicator 41); microprocessor malfunction (box 42, light 43), need to fold or erect the scale (box 44, light 45), malfunction of a sensor with display of the sensor number (box 46, digital display 47) , tilt correction fault (indicator 48) boxes 49, 50 being free here with additional indicator lights.

Figure 7 shows the block diagram of the hydraulic movement control circuit.

A variable flow pump 52 supplies the entire installation from a reservoir 53. The telescopic beams which support the chocks are controlled by distributors 54 and 55 which respectively supply the jacks 56 of the left beams and the cylinders 57 of the right beams. A distributor 58 ensures the actuation of cylinders 59 for neutralizing the elastic suspension of the vehicle and of the timing cylinders 2. When the timing cylinders 2 are resting on the ground, a pressure switch 60 registers the resulting pressure increase and it establishes the energizing the electronic system of the ladder via input E1. Therefore, the control of the movements of the scale itself is possible by action on the proportional solenoid valves 61, 62, 63 and 64.

The solenoid valve 61 controls the deployment-folding movement through the hydraulic motor 65 which actuates a winch. The solenoid valve 62 controls the dressing-lowering movement by means of the jacks 66.

The solenoid valve 63 feeds the tilt correction cylinders 67 which cause the part 5 of the turret to rotate.

The solenoid valve 64 controls the pivoting movement to the right or to the left by means of the motor 68.

Each of the solenoid valves 61, 62, 63, 64 is of the proportional type, that is to say it delivers a flow proportional to the control voltage of the coils. A solenoid valve 51 energized as soon as one of the solenoid valves 61, 62, 63, 64 is also energized, makes it possible to send to the pump 52 the information of maximum pressure necessary in the circuits which modifies the displacement of the pump so that it just delivers the flow required for use, at the pressure prevailing in the use circuit.

In the absence of control voltage for the solenoid valve 51, the flow rate of the pump 52 is zero. Thus in the event that an emergency stop is requested by the operator, input E13 of the microprocessor, the microprocessor cuts the electrical supply to the distributor 51, output S19 of the microprocessor (control oil pressure of the pump at zero value by exit status 0).

FIG. 8 shows the general flowchart of the operations carried out by the electronic microprocessor system.

• ― initialisation des mémoires ;
• ― lecture des entrées E1 à E51 et stockage en mémoire travail ;
• ― calcul des paramètres hauteur, portée ;
• ― comparaison de la portée réelle avec les portées limites ;
• ― calcul des valeurs maximales de longueur développée L, portée P, hauteur H possibles avant d'atteindre la prochaine limite à angle de dressage constant ;
• ― vérification si l'échelle est utilisée avec sa plate-forme de travail : si OUI, la vitesse maximale possible de chacun des mouvements Dressage/Abaissement, Déploiement-Reploiement, pivotement droite ou gauche, est réduite car dans ce cas l'échelle est susceptible d'être manoeuvrée avec du personnel dans la plate-forme. Dans le cas contraire, la vitesse maximale est simplement limitée par les composants hydrauliques et mécaniques ;
• ― arrêt d'urgence : si l'arrêt d'urgence (sécurité coup de poing, entrée E13) a été actionné, il y a arrêt de tous les mouvements par retour à zéro des électrodistributeurs 61, 62, 63, 64 et passage de la pompe 52 à débit nul comme précédemment indiqué. Ensuite, le programme se repositionne au début et se réexécute.

As soon as the vehicle is correctly chocked, the pressure switch 60 switches on the electronic system which starts up and performs the following operations:

• - initialization of memories;
• - reading of inputs E1 to E51 and storage in working memory;
• - calculation of the height and span parameters;
• - comparison of the actual range with the limit ranges;
• - calculation of the maximum values of developed length L, span P, height H possible before reaching the next limit at constant dressing angle;
• - check if the ladder is used with its working platform: if YES, the maximum possible speed of each of the Dressing / Lowering, Deployment-Folding movements, right or left pivoting, is reduced because in this case the scale is likely to be operated with staff in the platform. Otherwise, the maximum speed is simply limited by the hydraulic and mechanical components;
• - emergency stop: if the emergency stop (punch security, input E13) has been activated, all movements are stopped by return to zero of the solenoid valves 61, 62, 63, 64 and passage of the pump 52 at zero flow as previously indicated. Then, the program is repositioned at the beginning and re-executed.

If the emergency stop is not requested, the program continues.

Checking the value of the dressing angle α:

If it is less than or equal to 20 ° the influence of the superelevation on the scale is negligible and the scale must be at the position corresponding to a zero superelevation (δ = 0) in order to possibly allow a return of the scale on its road support.

If it is not, the movements are stopped and the scale is reset to the position δ = 0.

If it is greater, there is verification that the tilt correction is carried out and that the maximum allowed tilt is not reached (Entry E24). Otherwise, movements are stopped to correct the slope and return to the start of the program.

The program then includes the scale overload test (Input E51).

If YES, there are movements that aggravate the load case, which are deployment and lowering, and continuation of the program by examining the other movements.

If NO, the program continues.

The program then includes the successive control of the different movements:

The principle of movement control is the same for all movements except the folding back, for which the automatic concordance of the steps can be superimposed.

These lowering, unfolding, then straightening movements are controlled as follows:

• NON : maintien ou mise en position d'arrêt de ce mouvement.
• OUI : ce mouvement est-il en fin de course ou engendre-t-il un choc ?
• Si OUI : arrêt du mouvement.
• Si NON : poursuite du programme.

Is the movement requested by the operator? (Inputs E41 to E43)

• NO: hold or stop this movement.
• YES: is this movement at the end of the race or does it cause a shock?
• If YES: movement stopped.
• If NO: continuation of the program.

• Si NON : le mouvement est exécuté à la vitesse demandée.
• Si OUI : la vitesse maximale possible en fonction du prochain arrêt est déterminée par le microprocesseur et le mouvement est exécuté à cette vitesse si la vitesse demandée est supérieure ou égale à cette vitesse (voir description plus loin).

Is this movement approaching an automatic stop (slowed zone)?

• If NO: the movement is executed at the requested speed.
• If YES: the maximum possible speed according to the next stop is determined by the microprocessor and the movement is executed at this speed if the requested speed is greater than or equal to this speed (see description below).

• Si NON : il y a arrêt du reploiement.
• Si OUI : il y a reploiement lent de l'échelle dans le cas où les échelons ne sont plus en concordance, ou arrêt s'il sont déjà en concordance.

Deployment: the principle is the same except that if the movement is not requested, the system checks whether the automatic matching of the steps is requested:

• If NO: the folding is stopped.
• If YES: there is a slow folding of the scale in the case where the steps are no longer in agreement, or stopping if they are already in agreement.

Checking the dressing angle α:

Greater than or equal to 70 °: the pivoting maneuver is stopped because by the backlash of the chassis the angle of dressing can increase. Then the program resumes at the start.

Lower than 70 °: there is control of the swiveling movements to the right or to the left in a similar way to the other movements then return to the beginning of the program.

Figures 9, 10 and 11 show the detailed flowchart for the calculation of heights and spans, the memorization of the position of the support beams of the stabilizer jacks, the display of the authorized load limits and the storage of the limit range corresponding to the operating case.

As indicated in the “calculation” box of FIG. 9, the microprocessor after having read all the input parameters, calculates the range P, the height H, the maximum values of developable length L maxi before automatic stop at constant angle of dressing and corresponding maximum height H, the maximum value of the dressing angle α2 corresponding to the maximum range for which there must be an automatic stop at constant developed length L; the angle of dressing αr, the range Pr and the developed length Lr at the start of slowing down of the movements. Δα corresponds to an angular range of deceleration of the lowering before automatic stop, and ΔP and ΔL to two ranges of deceleration before automatic stop in range or developed length.

The different values taken into account are stored in memories indicated in the “Calculation” box of FIG. 9, by the letter M followed by an identification index. For these calculations, the microprocessor uses the memory M20 in which the maximum range corresponding to the use of the scale is stored (fig. 3 and 11).

When switching on this memory is initialized. The values thus calculated are displayed on the outputs indicated in the "Display" box.

The microprocessor then checks in what position the timing cylinders 2 are and what is the orientation θ of the scale relative to the longitudinal axis of the vehicle. If the orientation θ of the scale does not differ by more than ± 25 ° from the longitudinal axis of the vehicle, the useful range is the maximum range for the load considered and it is independent of the position of the stabilizers. For different orientations of the scale, the microprocessor memorizes the position of the beams located on the side where the scale is oriented (memories M2, M3, M4, fig. 9).

The microprocessor then displays the load case (fig. 10). It examines whether the ladder is used with or without its platform (entry E9) what is the choice of load made by the user (1, 2 or 3 men on the platform, resting ladder, entries E10, E11, E12) and it compares, in the case of the scale used without a platform, the actual range of the scale stored in the memory M21, with the limit ranges authorized as a function of the position of the stabilizers; it deduces the maximum possible load therefrom and proceeds to switch on the corresponding warning light and extinguish the other warning lights by outputs S3 to S9 (warning lights 33 to 39).

The microprocessor then checks if there is a concordance of steps and displays the corresponding display (LED 41).

The following sequence relates to the emission of an audible signal when there is a change of load case; thus an audible signal of duration 1 second is emitted when the range becomes equal to P4, P5, P6, P7, P8 or P9.

The following sequence (fig. 11) assigns to memory M20 the maximum range (display 30) corresponding to the use of the scale and displays it (output S30). The microprocessor then proceeds to limit the maximum possible speeds of the movements in the case where the scale is used with its platform, as already indicated (test passing through E9).

The operating principle of motion control is described using FIG. 12, taking the example of the lowering of the scale (with analog signals in the form of voltage).

The operator, via a Dressage / Lowering control manipulator, requests the lowering of the scale and sends a voltage proportional to the requested speed to the electronic system. The command and control system checks whether the requested movement can be executed according to the various safety parameters entered in the program and generates, if there is compatibility, the control signal (output S33) which will be taken into account by the solenoid valve (62) for controlling the movement in question. The movement commands, in the example chosen, are done as follows: $$\begin{array}{c}\begin{array}{c}\text{E41 = 0 Volt (± 1 V) = no movement}\\ \text{- 1 Volt>E41> - 6 Volts = request to lower}\\ \text{+ 1 Volt <E41 <+ 6 Volts = request for training.}\end{array}\end{array}$$

As indicated in the flow diagram of FIG. 12, the MPU compares the analog value E41 (stored with RAM) with the value - 1 Volt (stored in REPROM). Two cases can occur. $$\begin{array}{c}\begin{array}{c}\text{E41 ≧ - 1 Volt = no reduction required}\\ \text{E41 <- 1 Volt = lowering required.}\end{array}\end{array}$$

If the result of the comparison is "no lowering requested", the MPU sets the output S33 to 0 (or maintains it if it was previously there).

If the result is "lowering requested", the MPU checks, in the order of the program, the logical values of the inputs E18, E25 and E29 (stored in RAM). If one of them is at 1, the output S33 is set (or maintained) at 0.

Then comes the verification of the position of the ladder in relation to the pivoting and straightening / lowering chassis to avoid any interference with the vehicle cabin (tests A and B).

If A and B are positive, the MPU sets S33 to 0.

If A is positive and B negative, test C is done.

If C is positive: the analog output S33 generates a signal proportional to the input E41 with a decreasing maximum value in accordance with a deceleration curve with end of travel stop, REPROM memory storage and which will be seen later.

If A is negative or C, the MPU checks logic input E27 (test D) and test E.

If D or E is positive, the output S33 generates, as above, a signal proportional to the input E41 with maximum value limited by said deceleration curve before end of travel.

If D and E are negative, the MPU generates a signal proportional to the input E41 without correction except in the event of a sudden request or suppression of the motion control (input E41) or in this case the MPU generates the output signal at l acceleration and deceleration, according to other speed control curves stored in REPROM memory, this in order to have greater comfort in piloting the ladder and to avoid unpleasant mechanical stresses on the ladder.

In the case of using a platform 11 at the end of the scale, the MPU which manages the output S33 can, without waiting for a deviation from the horizontality of the platform, simultaneously control its alignment by generating a proportional signal to S33 on the output S36: proportional control for horizontal positioning of the platform 11, this proportional control being able to cooperate with an actuator not shown, such as an electric actuator interposed between the last rung 10 of the scale and the platform to vary the angle β.

In addition, a control loop is incorporated into the program, which allows, by measuring the angle β of the platform with respect to the scale (E45) to put in the program a correction parameter making it possible to remove the deviations due to the electro-hydro-mechanical system for controlling the power of the ladder's movements.

The training command is controlled and executed by the MPU according to the same principle as the lowering command above, with of course, parameters to control specific to this movement.

The control of the deployment and folding movements is done on the same principle as the command of lowering and straightening according to the input E42, safety tests specific to these movements, to generate a signal proportional to the output S34 = Deployment / Deployment proportional control.

For the control of pivoting movements to the right or to the left, the MPU, as for the control of lowering and straightening, but depending on the input E43 and tests specific to these movements, generates a signal proportional to the output S35 = Proportional control of Swiveling to the right or to the left.

FIG. 13 defines the principle flow diagram of the automatic slowing down of the pivoting, lowering or deployment movements before automatic stopping, corresponding to the maximum admissible range.

The microprocessor receives the operator's movement orders. If the range P is greater than or equal to the maximum admissible range Pa, the microprocessor does not control the movement.

If the range P is less than the maximum admissible range Pa, the microprocessor compares the range P with the range Pr corresponding to the start of the zone where the movement must be slowed down in order to reach the automatic stopping point at zero speed.

Figure 14 illustrates the diagram of the speed of movement as a function of the space traveled. In the zone A corresponding to a range P less than or equal to Pr, the speed of the movement is that requested by the operator and it can go up to the maximum speed Vm allowed by the control systems.

In zone B corresponding to a range P greater than Pr and less than Pa, the microprocessor imposes a maximum speed defined by the limit C which joins the point of start of deceleration where the speed can be maximum at the point of end of deceleration where the speed must be zero.

In zone B the microprocessor controls the movement at the speed requested by the operator as long as this is lower than the limit speed defined by curve C, then at the speed corresponding to this curve C when the speed requested by l operator becomes superior to the latter. Such a movement slowdown system is only effectively achievable thanks to the use of a microprocessor because the slowdown zones of each movement are a function of the large number of parameters on which the limit range Pa depends and they must be constantly recalculated in course of movement, as we have seen, the various movements of the scale being able to be simultaneous and influencing the limit range Pa. The microprocessor thus limits in all cases the harmful dynamic effects and in particular any swinging of the undesirable scale.

More particularly, the slowing down of the various movements can be controlled in the following manner by the microprocessor.

Slower development and lowering movements:

When the range P is between the ranges Pr and Pa, the microprocessor calculates the maximum admissible speed for each movement corresponding to a progressive deceleration. For this, each movement is considered as if it were executed alone, this being possible only thanks to the very high calculation speed of the microprocessor.

Development (see figs. 15 and 16):

At the instant t the end of the scale is in N at a distance x from the area of the automatic stopping point. The space L being divided into n1 no deceleration, the Maximum speed of development compatible with the progressive deceleration is given by the following relation: $${\text{V}}_{\text{Lm}}{\text{(N) = V}}_{\text{LMaxi}}\text{[1- (1 / n1) x | (ΔL-x) / (ΔL / n1) |]}$$

The microprocessor which has in memory the speed-command relation S34 of the development movement, determines the maximum command command S34 _m which corresponds to the maximum admissible speed V _Lm (N).

Lowering (see fig. 17 and 18):

in the same way as for development we have: $${\text{Vα}}_{\text{m}}{\text{(R) = Vα}}_{\text{Maxi}}\text{[1- (1 / n2) x | (Δα-y) / (Δα / n2) |]}$$

The microprocessor which has in memory the speed-command relationship S33 of the lowering movement determines the maximum command order S33 _m which corresponds to the maximum admissible speed Vα _m (R).

Swivel (see fig. 19 and 20);

et si ${\text{θ}}_{\text{r}}{\text{<θ < θ}}_{\text{a}}$

le mouvement de pivotement est ralenti progressivement entre θ_r et θ_a de la même façon que précédemment et la vitesse maximale admissible est donnée par : $${\text{V}}_{\text{θm}}{\text{(T) = V}}_{\text{θMaxi}}\text{[1-(1/n3) x |(Δθ-z)/(Δθ/n3)|]}$$

During pivoting, the range Pa corresponding to the automatic stop may change, for example when the scale deviates from the longitudinal axis of the vehicle and the beams of the jacks are retracted or half-extended. In this case, if the end T of the scale corresponds to a range greater than the admissible value for ${\text{θ> θ}}_{\text{at}}$

and if ${\text{θ}}_{\text{r}}{\text{<θ <θ}}_{\text{at}}$

the pivoting movement is gradually slowed down between θ _r and θ _a in the same way as above and the maximum admissible speed is given by: $${\text{V}}_{\text{θm}}{\text{(T) = V}}_{\text{θMax}}\text{[1- (1 / n3) x | (Δθ-z) / (Δθ / n3) |]}$$

The microprocessor which has in memory the speed-command relation S35 of the pivoting movement, determines the maximum command command S35 _m which corresponds to the maximum _admissible speed V _θm (T).

As a variant, it is possible to carry out a range law as a function of the pivoting angle such that the trajectory of the end of the scale projected on the horizontal plane is parallel to the longitudinal axis of the vehicle in the sector where there may be a risk of tilting, this law being illustrated by the curve (C) represented in FIG. 19.

FIG. 21 defines the principle flow diagram for the horizontal positioning of the working platform 11.

To keep the work platform horizontal, the microprocessor simultaneously controls the angular movement of the platform and the raising or lowering of the ladder at the same speed. To avoid the risks of drift, sensors of known types such as potentiometers or angular encoders measure the angle of dressing α and the angle β of the platform floor relative to the scale.

In the event of a deviation, the microprocessor calculates the speed necessary to follow the raising or lowering movement and to remove the position deviation after a defined time, for example 5 seconds.

This device which performs the simultaneous angular movement of the platform 11 and of the ladder makes it possible to have the platform horizontally precise and smoothly, which improves the comfort of the passengers.

When the operator requests a movement which becomes dangerous for the stability of the vehicle, the microprocessor thus causes, as explained, the automatic stopping of this movement when the limit is reached, after having achieved the progressive deceleration of this movement.

The movement being stopped, the light requesting training or folding back (S11 - light 45, fig. 6) lights up.

The operator, who may be in a context of panic, may not react immediately and wonder why the ladder is no longer ordered. It is then that the transmission of a spoken message takes on its full value and is here provided from the microprocessor according to the diagram in FIG. 22.

The microprocessor at this time, sends by BUS, the information necessary for the dissemination of the message corresponding to the scenario that caused the automatic shutdown. The memory circuits 69 and speech synthesizer 70 manufacture the sentence to be broadcast which, after amplification at 71 is transmitted to a loudspeaker 72 placed near the ladder operator acting in the vehicle. A second listening station 73 can be placed at the ladder control station located in the platform 11 to inform an operator acting from the platform.

The use of a microprocessor also allows greater ease of adaptation to particular constraints. Thus, when the ladder or the lifting arm is mounted on different types of chassis-cabin, the operating limits change and it suffices to modify the values stored in memory. Likewise, if modifications or options are requested in the security system, it suffices to add additional sensors if necessary and to modify the program. This means that many variants can be easily adapted while remaining within the scope of the invention.

Claims (8)

1. Control device for a rotatable, extendable ladder, or similar lifting arm, provided with an articulated platform suitable for transporting one or more persons, comprising at least a control for raising and lowering, a control for extension and retraction and a control for pivoting, with manual means for selecting the movements desired, and actuators for raising and lowering, for extension and retraction and for rotation, said selecting means being suitable for supplying electrical signals representative of the control direction and the desired speed of execution of the movements desired, characterised by the fact that it comprises a control signal reading microprocessor receiving said electrical signals, said microprocessor comprising in memory: the maximum reaches, not to be exceeded, according to different selectable and pre-determined parameters for operation of the ladder, including pre-determined loading options and pre-determined ladder orientations; a cyclic sequence of calculation of the actual reach from data supplied by sensors for measuring the angle of raising and the length extended; a cyclic sequence of comparison of the calculated actual reach with the maximum reach corresponding to pre-defined operating conditions and authorising or not the movement requested, by the fact that said microprocessor comprises in its memory a law for deceleration, at least for the lowering and extending movements in terminal zones pre-determined for the course of these movements, corresponding to a certain approach to the maximum pre-determined operating reach corresponding to the circumstances in which the ladder is being operated, taking into account the load selection made by the user, said terminal zones being limited by said pre-determined maximum operating reach and being continuously recalculated by the microprocessor during movement, and by the fact that the microprocessor comprises in its memory a cyclic sequence of comparison, in this approach, of the control speed indicated to the speed derived from said rule for each movement concerned, intended for applying said rule when the indicated control speed is excessive, by supplying to the outputs of the microprocessor controlling these movements signals representing the indicated control speed, or automatically modified according to said rule, to obtain the maximum pre-determined reach at zero speed, said outputs being connected to electrical proportioning control means for activating actuators for the movements concerned.
2. The control device according to claim 1, characterised in that the microprocessor contains in its memory a law of acceleration for the start up and a law of deceleration for stopping, imposed in response to any signal of voluntary command for starting up or stopping for each movement considered.
3. The control device according to claim 2, characterised in that it includes sensors of the maximum allowable positions for the movements considered, imposing the law of deceleration before stopping.
4. The control device according to any of the preceding claims, characterised in that to the microprocessor is associated a memory of instructions selectively activated in response to diverse border-line cases to stop automatically the movements considered and connect to a voice synthesizer to emit spoken messages of instructions for the information of the operator.
5. The control device according to any of the preceding claims, characterised in that it includes, connected to the microprocessor, display circuits for the determined limiting values of the maximal reach and corresponding developed length and angle of raising and lowering, for the actual values of extended length and vertical angle measured by sensors, and for the corresponding calculated reach.
6. The control device according to any of the preceding claims, characterised in that it includes, connected to the microprocessor, an audible warning system of temporary activation for the pre-determined changes of the limiting maximal reach, corresponding to changes of the case of possible load appearing on the display equally connected to the microprocessor.
7. The control device according to any of the preceding claims, characterised in that it includes, connected to the microprocessor, an audible warning system of temporary activation for the entry into use of the said law of automatic deceleration to forewarn of an imposed slowing before an automatic full stop.
8. The control device according to any of the preceding claims, for a ladder or lifting arm including a platform at its articulated end and an activator to horizontal position of the platform, characterised in that it includes a sensor for the measurement of the angle of the platform relative to the ladder or arm and that the microprocessor contains in its memory a sequence of cyclic comparisons of values supplied by the sensor of the measure of platform angle, in order to apply to an output of the microprocessor connected to an instrument of electric control proportional to the activator of horizontal position, a signal derived from the signal of control of the speed of raising or lowering in the absence of difference of comparison, or a corrected signal according to the difference of comparison by a sequence of cyclic correction provided within the microprocessor.

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