JPH0522444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a traveling vehicle that is applied to, for example, a floor traveling type work robot and has a traveling mechanism capable of traveling on stairs and climbing over a weir.

[Technical background of the invention and its problems]

Currently, operators conduct on-site inspections at various plants and factories. Among these tasks, there is a need for the development of robots that can perform simple tasks and nighttime monitoring for the purpose of reducing the burden on humans and making inspection and monitoring more reliable. In addition, in various plants and factories, the objects to be inspected are wide-ranging, so the inspection robot needs a moving mechanism that moves, for example, on the floor.

Furthermore, since this inspection robot is intended to perform on-site inspections on behalf of operators, it is currently required to be able to move freely through existing facilities such as plants and factories, corridors, stairs, etc. be done. For this reason, vehicles are being developed that use crawlers and the like to climb stairs and climb over weirs.

However, in this conventional traveling vehicle, the torque of the drive motor was set to match the load when driving on stairs and weirs, which is much more severe than when driving on flat ground, so the motor became larger and the reduction ratio of the gear was made large to ensure torque. For this reason, it was not possible to reduce the size and weight, and the running speed was compromised. Another method is to provide a clutch and a speed change gear, but since there are generally multiple crawlers (two or four pairs), a plurality of clutches and speed change gears are also required. For this reason, the weight of the tower mounting space becomes large, and the effect is ultimately ineffective. Moreover, since the configuration is complicated, there are problems such as a lack of reliability and maintainability.

Generally, when a battery-mounted vehicle drops to a predetermined voltage, it issues a low battery warning and returns to a predetermined position, such as a charging station. That is, in order to return to the predetermined position, it was necessary to have sufficient battery margin. However, since this detection point does not have a large difference from the normally used voltage, it has the disadvantage of causing detection errors.

[Purpose of the invention]

The purpose of the present invention is to prevent a reduction in the speed of normal travel due to an increase in the size of the drive motor or a significant gear reduction for some exceptional travel such as stair travel and climbing over a weir, and to enable stair travel with a simple configuration. The present invention also provides a traveling vehicle that can overcome weirs.

[Summary of the invention]

The traveling vehicle according to the present invention is equipped with a detector for detecting stairs and a weir while traveling, a temperature detector for detecting the coil temperature of the drive motor, an auxiliary battery, a controller, and a switching device to detect stairs. In response to the detector signal that is detected, the battery normally used in a switch for stairs and the like is connected in series with the auxiliary battery, and the voltage applied to the drive motor is increased to generate a high torque higher than the rated value. The present invention is characterized in that the coil temperature is detected by a temperature detector and the coil temperature is operated within a predetermined temperature rise limit.

[Embodiments of the invention]

The present invention will be described below with reference to embodiments shown in the drawings. In FIG. 1, a traveling vehicle 1 according to the present invention includes a crawler 2 capable of running on stairs and climbing over a weir, and a detector for detecting stairs, etc., which is a narrow field of view type and a diffuse reflection type photoelectric detector having a predetermined detection distance. A detector 3 is provided. Also, this floor traveling vehicle 1
Although not shown, the vehicle has a steering mechanism, a traveling mechanism, and a control device, and travels along a predetermined travel route on the floor 4 or the like according to a program, or by remote control such as by radio.

On the other hand, a photoelectric detector 3 installed at the front of the vehicle 1
is constructed by arranging a required number of photodetectors 3a, 3b, 3c, 3d, and 3e in a direction perpendicular to the floor surface 4. In FIG. 2 showing a block diagram of the photoelectric detectors 3a to 3e, a light projector 11 is connected to an oscillation circuit 12.
It consists of a light projecting element 13 and a lens 14.
The light receiver 15 also includes a lens 16, a light receiving element 17, an amplifier circuit 18, and a synchronous rectifier circuit 19.

Next, the operation of this photoelectric detector 3 will be explained. First, an oscillation circuit 12 oscillates a constant frequency, and a light emitting element 13 using a light emitting diode or the like is modulated on and off. The emitted light passes through a lens 14 and is irradiated onto an object to be detected, such as stairs, and the reflected light passes through a lens 16 and enters a light receiving element 17 using a phototransistor or the like. And light receiving element 17
is converted into an electrical signal. Of this electrical signal, only the modulated signal is amplified by the amplifier circuit 18. Next, in order to distinguish it from noise etc., only the signal having the same frequency as the oscillated signal is rectified by the synchronous rectifier circuit 19.
This rectified signal becomes an output signal of the light receiver 15 and is output to the determination circuit 20. The signal input to the determination circuit 20 is compared with a preset reference value, and if it is equal to or greater than the reference value, it is converted into an "on" signal, and if it is less than the reference value, it is converted into an "off" signal.

In addition, photoelectric detectors 3a, 3b, 3c, 3d, 3
e has a light projection characteristic as shown in FIG. That is, according to this characteristic diagram, the detection distance L
If there is a detection object within the projected light width, that is, within the detector W, the determination circuit 20 sends an "on" signal. The detection distance L and detection width W are
It can be changed by changing the detection sensitivity, that is, the gain of the amplifier circuit 18 and the reference value of the determination circuit 20. For example, the detection distance L is set to about 30 cm, and the detection width W is set to about 2 cm.

Next, the control system of this traveling vehicle 1 is shown in the block diagram of FIG. In FIG. 4, the controller 30
A photoelectric detector 3 and a drive circuit 31 are connected to the photoelectric detector 3, and a drive motor 32 is connected to the drive circuit 31. Further, an encoder 33 connected to the rotating shaft of the drive motor 32 and a temperature detector 34 attached to a coil end of the drive motor 32 are connected to the controller 30. On the other hand, a battery 35 for normal use is connected to the other end of the drive circuit 31, a switch 36 is connected to the other end of the battery 35, and an auxiliary battery 37 is connected to the switch 36. Further, the switch 36 is connected so as to be operated by the output signal of the controller 30. Note that 38 is a diode.

Next, the operation of the control system shown in FIG. 4 of the traveling vehicle 1 of the present invention will be explained using FIGS. 5 to 7. The traveling vehicle 1 freely travels by steering the crawler 2 and driving the drive motor 32 connected to the crawler 2 by the drive circuit 31 based on predetermined program data or remote control instructions from the controller 30. When the stairs 40 are in front of the vehicle 1, the vehicle 1 is located at the bottom step 4 of the stairs.
0a within the detection distance L of the photoelectric detector 3, the output of the photoelectric detector 3a becomes "on". When the traveling vehicle 1 further moves in the direction of the arrow A and approaches the stairs 40 by a distance _L1 , the distance between the stairs 40b and the photoelectric detectors 3b and 3c becomes the detection distance L, and each becomes "on".

In other words, here the depth of one step is higher than the photoelectric detector 3a and lower than the photoelectric detector 3b.
The controller 30 can determine that the staircase is _L1 . Here, the distance _L1 can be detected from the value of the encoder 33 that detects the travel distance. Furthermore, for example, by setting the setting position of the photoelectric detector 3b to the limit of the level difference in which the vehicle 1 can run, the difference in level is lower than the mounting height of the photoelectric detector 3b in the embodiments shown in FIGS. 5 and 6. It is possible to determine that the staircase 40 is one that the vehicle 1 can climb.

When the traveling vehicle 1 detects the stairs 40 by the photoelectric detector 3 in this way, the control circuit 30 shown in FIG. Then, a voltage higher than the rated voltage (hereinafter referred to as overvoltage) is applied to the drive motor 32 so that high torque can be obtained. Generally speaking, the torque characteristics with respect to the voltage of the motor 3
As shown in FIG. 8, as the voltage increases, the starting torque increases, for example, in proportion to the square of the voltage, although this differs depending on the type. Then, due to the driving force of the drive motor 32 whose torque has been increased by applying an overvoltage, the traveling vehicle 1 is moved to the first step of the stairs 40.
Climb a.

Next, as shown in FIG. 6, the vehicle 1 climbs the stairs 40. Passage of the stairs 40 can be detected from the encoder value for detecting travel distance. After passing the stairs 40, the controller 30 sends a command to the switch 36 to open the contact 36a, disconnect the auxiliary battery 37 from the battery 35, and return to normal rated operation.

Note that when the vehicle is operated with overvoltage, such as when running on the stairs 40, the coil temperature of the drive motor 32 increases. This temperature rise is detected by a temperature detector 34 such as a bimetal, and the temperature rise limit of the coil insulation material is determined.
For example, if the temperature rises to 130℃ or more, the controller 3
Send a signal to 0. At this time, the controller 30 is asked to open the contact 36a of the switch 36 or the drive circuit 31
A command is sent to stop the drive motor 32. When the temperature detector 34 detects that the coil temperature has decreased to a predetermined temperature, the predetermined operation is restarted.

On the other hand, the traveling vehicle 1 can detect walls and weirs using the photoelectric detector 3. That is, when the vehicle 1 approaches the wall 50 by a distance L as shown in FIG.
are in the "on" state at the same time, and it is possible to detect that the detection object is higher than the photoelectric detector 3e.
That is, it can be determined based on the wall 50 and the controller 30. Furthermore, the same method can be used to detect a weir. For example, if only the photoelectric detector 3a is "on" and the same is true after traveling distance L, it can be determined that the weir can be climbed over. Furthermore, if the photoelectric detector 3b turns on at the same time as the photoelectric detector 3a, it can be determined that the weir cannot be overcome.

Furthermore, in the control block diagram of another embodiment shown in FIG. 9, a voltage detection circuit 60 is provided to detect the voltage of the battery 35, etc., and a contact point is provided to the switch 36 to connect the battery 35 and the auxiliary battery 37 in parallel. 36b and a contact 36c that disconnects the battery 35 from the drive circuit 31 is provided.

The operation of this other embodiment shown in FIG. 9 will be explained with reference to the battery discharge characteristic diagram shown in FIG. 10. 1st
Point A in Figure 0 is the conventional detection point for battery reduction. However, in the vehicle 1 of the present invention, it is possible to detect the battery voltage at point B, which is significantly lower than the normally used battery voltage. That is, the voltage detection circuit 60 detects a voltage drop to point B and sends a signal to the controller 30. The controller 30 closes the contact 36a of the switch 36 to connect the battery 35 and the auxiliary battery 37 in series, or closes the contact 36b of the switch 36 to connect the battery 35 and the auxiliary battery 37 in parallel, or By closing the contact 36b of the switch 36 and opening the contact 36c to disconnect the battery 35 from the drive circuit 31 and connect the auxiliary battery 37, it is possible to return to a predetermined position such as a charging station by itself.

Overall, according to the vehicle 1 according to the present invention, the vehicle 1 is equipped with a photoelectric detector 3, an auxiliary battery 37, a switch 36 between the normally used battery 35 and the auxiliary battery 37, a voltage detection circuit 6, a controller 30, etc. The photoelectric detector 3 automatically detects stairs and weirs, the switching device 36 connects the normally used battery 35 and the auxiliary battery 37 in series, and operates the drive motor 32 with overvoltage. Since the vehicle is configured to obtain high torque, there is no need to increase the size of the drive motor for some exceptional driving such as stairs, and the traveling vehicle 1 can be made smaller and lighter. be.

In addition, there is no need to increase the reduction ratio of the gear to ensure the high torque required for running on stairs, etc., and there is no need to provide a clutch or high-speed gear, etc. The configuration is simple and maintainability and reliability are high.

Further, when the drive motor is operated at an overvoltage, there is a problem in that the temperature of the coil of the drive motor increases. However, although this varies depending on the ambient temperature, there is usually no problem with driving for a few minutes, which is enough time to pass through certain areas such as stairs and weirs. Furthermore, since the temperature detector is configured to be able to detect when the temperature of the coil end has exceeded the temperature rise limit, accidents such as burnout of the drive motor can be prevented.

Furthermore, when the voltage of the normally used battery drops significantly due to the voltage detection circuit, it is possible to connect the auxiliary battery and reliably return to a predetermined position, such as a charging station. Additionally, photoelectric detectors have the function of detecting obstacles, so they are effective in preventing collisions with moving vehicles.

〔Effect of the invention〕

As described above, according to the present invention, in a traveling vehicle equipped with a traveling mechanism capable of running on stairs and climbing over a weir, a detector for detecting the presence of stairs and a weir;
A battery and an auxiliary battery are mounted on the tower, and when the detector detects the presence of the stairs and a weir, the connection of the battery and the auxiliary battery is switched to generate high torque in the drive motor. For some exceptional maneuvers such as traveling and going over weirs, the drive motor is specially made larger or a large gear reduction is required to prevent the normal traveling speed from decreasing. It has the advantage of making it possible to overcome.

[Brief explanation of the drawing]

FIG. 1 is a front view of a traveling vehicle according to the present invention, particularly showing how the photoelectric detector is installed, FIG. 2 is a block diagram showing the configuration of the photoelectric detector used in the present invention, and FIG.
Fig. 4 is a block diagram showing an embodiment of the control system of the vehicle according to the present invention, and Figs. Explanatory diagram for explaining, 7th
The figure is an explanatory diagram showing a wall detection state of a traveling vehicle according to the present invention.
Fig. 8 is a characteristic diagram showing the relationship between torque and voltage of the drive motor, Fig. 9 is a block diagram showing another embodiment of the control system for a traveling vehicle according to the present invention, and Fig. 10 is a battery discharge characteristic diagram. . DESCRIPTION OF SYMBOLS 1... Traveling vehicle, 2... Crawler, 3... Photoelectric detector, 4... Floor surface, 11... Light emitter, 15... Light receiver, 20... Judgment circuit, L... Detection distance, W...
...Detection width, 30...Controller, 31...Drive circuit,
32... Drive motor, 33... Encoder, 34
... Temperature detector, 35 ... Battery, 36 ... Switching device, 37 ... Auxiliary battery, 40 ... Stairs, 5
0...Wall, 60...Voltage detection circuit.

Claims (1)

[Scope of Claims] 1. In a traveling vehicle 1 which has a traveling mechanism capable of traveling on stairs and over weirs and is driven by a battery-powered drive motor 32, an auxiliary battery 37 is mounted and a staircase 40 that is present on the way is mounted. or a weir,
Detection is performed by a diffuse reflection type photoelectric detector 3 having a narrow field of view having a predetermined detection distance L and arranged in a plurality 3a, 3b, ... 3e in a direction perpendicular to the floor surface. Alternatively, when the controller 30 detects that a weir has been detected, a control device comprising a switch 36 and a controller 30 that connects the battery normally used for the drive motor 32 and the auxiliary battery 37 in series. A running vehicle characterized by the following features: 2. A temperature detector 34 is provided to detect the coil temperature of the drive motor 32, and the auxiliary battery 37 is disconnected by a switch 36 in response to the temperature detector 34 reaching a predetermined value or more of coil temperature rise. A traveling vehicle according to claim 1, characterized in that: 3 A voltage detection circuit 60 is provided to detect the voltage drop of the battery normally used, and when the voltage detection circuit 60 detects the voltage drop of the battery, the contacts 36a and 36c of the switch 36 are opened and the contact 36b is closed to assist the battery. Switching between the battery 37 and the auxiliary battery 37, opening the contacts 36b and 36c, closing the contact 36a and opening the series contact 36a,
The traveling vehicle according to claim 1, characterized in that the contacts 36b and 36c are configured to be closed and connected in parallel.