JPH044187B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drive control device for a motorized truck.

(Prior Art) Conventionally, various types of operating devices for powered trolleys have been put into practical use. These include those that use a joystick to control the speed and direction of a powered truck;
Some vehicles are equipped with an operating grip similar to an accelerator on a motorcycle, and the running speed is controlled by rotating the grip.

(Problem to be Solved by the Invention) However, the conventional methods that use joy sticks or rotate operating grips require considerable skill to operate, and are not easy for anyone to operate. The problem was that I couldn't do it.

(Means for Solving the Problems) Therefore, the present invention provides a measuring device for individually measuring the force applied to the cart by an operator at at least two positions, and Power is generated from a calculation device that individually calculates acceleration/deceleration based on the measured values, and a drive device that drives the two motors individually based on the calculated values from this calculation device. The present invention is characterized in that it is configured as a drive control device for an attached truck.

(Example) Hereinafter, the present invention will be specifically described based on an example shown in the drawings.

First, the first embodiment will be described. FIG. 2 shows the overall structure of the powered truck 1. As shown in FIG. In this example, the powered trolley 1 is formed into a rectangular parallelepiped shape,
A hand bar 2 is attached to the side surface 1a via a support rod 2a. On the other hand, two drive wheels 3 and 4 are provided at the rear of the lower surface of the powered truck 1, and one front wheel S is provided near the center of the front portion of the lower surface.

Next, the control circuit 25 for controlling the rotation of the drive wheels 3 and 4 will be explained based on FIG. First, the two support rods 2a, 2a mentioned above are provided with strain gauges 5, 5, respectively. This may consist of, for example, a resistance wire strain gauge, etc.
They are attached to the support rods 2a, 2a, respectively. In this example, the support rods 2a, 2a are given some flexibility in order to generate sufficient strain on the strain gauges 5, 5.

Signals from the strain gauges 5, 5 are input to the CPU 8 via A/D converters 6, 7, respectively. CPU 8 is a normal 8-bit microcomputer, and it includes RAM 9 and
ROM10 is connected. And ROM1
0 has a built-in control program for controlling the entire control circuit 25. Note that this control program will be described later.

Next, two D/A converters 11 and 12 are connected to the output side port of the CPU 8, and one of the D/A converters 11 and 12, the D/A converter 11, drives the drive motor 16. The other D/A converter 12 is connected to a drive control device 15 for driving the drive motor 18 .

The drive motors 16 and 18 are normal DC type servo motors, and are driven and controlled by the output currents from the drive control devices 13 and 15.

On the other hand, the drive motors 16 and 18 are provided with drive wheels 3 and 4, brakes 20 and 27, and speed sensors 17 and 19, respectively.

The speed sensors 17 and 19 are composed of tachogenerators and the like, and are connected to drive motors 16 and 19, respectively.
It is designed to output a voltage proportional to the rotation speed of 18. And this speed sensor 17, 19
The output signals from each A/D converter 1
1 and 28, the analog signal is converted into a digital signal and then input to the CPU 8.

The brakes 20, 27 are connected to the drive motor 16,
18, and its ON/OFF state is controlled by signals from the CPU 8 and the emergency stop switch 23.

Next, start switch 21, stop switch 2
2. The emergency switch 23 will be explained. The start switch 21 is a switch for simultaneously supplying current to the control circuit 25 and resetting the CPU 8, for example, and when turned on, current is supplied to each circuit and the CPU
8 is reset and a predetermined program is executed.

The stop switch 22 is for applying a brake to the powered truck 1, and when it is turned on, an interrupt is generated and the interrupt process shown in FIG. 7 is executed.

The emergency stop switch 23 is a switch for sending an emergency stop signal to the CPU 8, the drive control devices 13, 15, and the brakes 20 and 27. When this switch is turned on, the drive control devices 13, 1 immediately stop.
5 is turned off, brakes 20 and 27 are activated,
It also has the function of holding CPU8. This emergency stop switch 23 is for CPU8
The brakes can be applied directly without passing through the system, increasing safety in emergencies.

Next, the action and effect will be explained. first,
The basic control pattern in this example will be explained based on FIG.

First, as a first pattern, when the output from the strain gauge 5 is 0, it is determined that it is a stop condition, and the acceleration and vehicle speed are set to 0 to stop the motorized truck 1.

Next, as a second pattern, the output from the strain gauge 5 is + (i.e., the hand bar 2
is being pushed forward. ) and when the rotational speed of the drive wheels 3 and 4 is 0, it is determined that the start condition is met, and the acceleration instruction is set to +. Therefore, the speed of the powered truck 1 gradually increases from zero.

As a third pattern, when the output from the strain gauge 5 becomes 0 while the powered truck 1 is traveling at a predetermined speed, a slight deceleration instruction is issued. This corresponds to the fact that, for example, if you release your hand while pushing a light trolley, the trolley will move forward while slowly decelerating.

As a fourth pattern, when the output from the strain gauge 5 becomes positive while the powered truck 1 is traveling at a predetermined speed, it is determined that an acceleration condition exists and an acceleration instruction is given.

The fifth pattern is when the output from the strain gauge 5 becomes negative while the powered trolley 1 is traveling at a predetermined speed (i.e., when the hand bar 2
(when the vehicle is pulled backwards), it determines that a deceleration condition exists and decelerates.

The above is the basic acceleration instruction pattern in this example. However, since the backward movement control of the powered truck 1 is the same as the forward movement control described above, the explanation thereof will be omitted here.

Next, specific details of the control will be explained based on the flowchart shown in FIG.

First, when a power switch (not shown) of the control circuit 25 is turned on, the main routine shown in FIG. 4 written in the ROM 10 starts. When this routine starts, first, in step 100, each part is initialized.
At the same time, the brakes 20 and 27 are turned on to prevent the motorized truck 1 from running carelessly. When this is completed, in step 101 the process waits for input from the start switch 21. When the start switch 21 is turned on here, the process proceeds to step 102, where the brakes 20 and 27 are turned off to make it possible to run, and the drive control device 1
Turn on 3,15.

When this is completed, the process proceeds to timer processing 103 and waits for a predetermined time. This step 103 is a timer routine for determining the cycle of the main routine, and it is thereby possible to set the sampling time of data from the strain gauges 5, 5.

When the waiting time in step 103 ends, the process advances to step 104, where data is input from the strain gauges 5,5. The data input from the strain gauges 5 and 5 is converted from analog to digital by A/D converters 6 and 7, respectively, and then input to the CPU 8, where it is converted into stress based on a predetermined program ( This corresponds to step 105).

When the processing in step 105 is completed, step
Proceed to 106 and install speed sensor 1 for left and right drive wheels 3 and 4
The rotational speeds of the drive wheels 3 and 4 are inputted from 7 and 19, respectively. When this input is completed, the process then proceeds to step 107, where acceleration is calculated. In this example, the acceleration in step 107 is calculated by subtracting the currently sampled velocity data from the previously sampled velocity data to determine the change in acceleration per unit time.

Once this acceleration has been calculated, the process proceeds to step 108, where it is determined whether the rotational speeds of the drive wheels 3 and 4 are 0 or not. If both rotational speeds are 0, the process proceeds to step 109, and if the rotational speeds are not 0, the process proceeds to step 111.

In both step 109 and step 111, it is determined whether the stresses detected by the strain gauges 5, 5 are respectively 0 or in the dead zone. Here, as shown in FIG. 5, the dead zone is a range in which the output from the strain gauges 5, 5 is considered to be 0 within a range where the force applied to the strain gauges 5, 5 is extremely small.

The judgment in step 109 and step 111 is NO.
In this case, the process advances to step 113, and the acceleration/deceleration corresponding to the stress determined in step 105 is read out from the map set in the ROM 10, and based on this, the drive motors 16, 16,
18 respectively.

Here, ROM10 referred to in step 113
To explain the map, it is as shown in Figure 5, where the range of low stress is a dead zone where acceleration is 0, and when stress is applied above a certain level, acceleration or deceleration is approximately proportional to this stress. It has come to be used as an instruction. (i.e.
Data with such a predetermined correspondence relationship is
This is written in the ROM 10 as data. ) On the other hand, if the judgment in step 109 is YES, the process advances to step 110 and the drive motors 16, 18 are
After setting the acceleration instruction to 0, step 103
It's starting to go back to.

Further, if the determination at step 111 is YES, the process advances to step 112 and the current drive motor 16,
Acceleration/deceleration according to each rotation speed of 18
A map set in the ROM 10 is read out, and the rotational speed of the drive motors 16 and 18 is controlled based on this.

Here, the ROM referenced in this step 112
The map 10 is as shown in FIG. 6, and is designed to indicate acceleration/deceleration approximately proportional to the rotational speed of the drive motors 16, 18. However, the acceleration/deceleration instruction in step 112 corresponds to the case where, for example, the operator stops pushing the powered trolley 1 while the vehicle is running, so it is similar to the gradual deceleration of a lighter trolley. The deceleration is becoming extremely gradual. When the process at step 112 is completed, the process returns to step 103 and the same process as described above is repeated.

In this way, the drive motors 16 and 18 are controlled in this main routine.

Now, to explain the correspondence between the control pattern shown in FIG. 3 and the flowchart shown in FIG. 4, when the control pattern shown in FIG. 110 and then returns to step 103.

At the start shown in the second pattern,
The process proceeds through step 108, step 109, step 113, and then returns to step 103.

Next, in the running state shown in the third pattern, steps 108, 111, and 112 are performed.
The process then returns to step 103.
Next, during acceleration control shown in the fourth pattern, the process proceeds through step 108, step 111, step 113, and then returns to step 103.

Furthermore, in the case of deceleration control shown in the fifth pattern, steps 108, 111, and 113 are performed.
The process returns to step 103.

Subsequently, control when the stop switch 22 or the emergency stop switch 23 is turned on will be explained.
First, when the stop switch 22 is turned on, an interrupt occurs, and control of the main routine shown in FIG. 4 is temporarily interrupted, and at the same time, the interrupt processing shown in FIG. 7 is started.

In this interrupt processing, a timer is first turned on in step 201. This is to prevent waiting time from occurring in step 202 when the first interrupt processing starts.
When you finish this step 201, the first step
Step 202 immediately proceeds to step 203, where it is determined whether the rotational speeds of the drive wheels 3 and 4 are within the speed range at which the brakes can be applied.

To explain the determination at step 203 in detail, a map as shown in FIG. 8 is set in the ROM 10. In this map, when the rotational speeds of the driving wheels 3 and 4 are both in the range of -V1 to V1, it is determined that the speed is such that even if the brakes are applied, the brakes will not suddenly brake, and the brakes 20 and 27 are turned on. It is now possible to apply the brakes.

On the other hand, if the rotational speed of the driving wheels 3 and 4 is V1 or more or -V1 or less, it is determined that the speed is such that sudden braking will occur if the brakes are applied, and the rotational speed of the driving wheels 3 and 4 is It is designed to indicate acceleration or deceleration depending on the speed. That is, for example, when the rotational speed of the drive wheels 3 or 4 is V2, a negative acceleration α2 is instructed.

The above explanation will be explained based on the flowchart shown in FIG. 7. If the judgment in step 203 is YES, the rotational speed is within a safe range even if the brakes 20 and 27 are turned on.
The program proceeds to step 205 to turn off the drive control devices 13 and 15, and turns on the brakes 20 and 27.Then, in step 206, the timer is reset, and then the process returns to the main routine shown in FIG. There is.

On the other hand, if the determination in step 203 is NO, that is, if the rotational speed of the driving wheels 3 or 4 is not within the speed range in which the brakes 20 or 27 can be turned on, the acceleration/deceleration is adjusted according to the rotational speed.
The instructions are read from the ROM 10.

When the process in step 204 is completed, the process returns to step 202 and the same process is repeated until the rotational speed of the drive wheels 3 and 4 reaches a speed range in which the brake can be turned on. Once the speed is within the allowable speed range, the process proceeds to step 205 and step 206, turns on the brakes 20 and 27, and then returns to the main routine.

Next, control when the emergency stop switch 23 is turned on will be explained. When this emergency stop switch 23 is turned on, this switch directly turns off the drive control devices 13 and 15, turns on the brakes 20 and 27, and puts the CPU 8 in a hold state. ing. Since the stop processing by the emergency stop switch 23 is directly performed by hardware without going through the CPU 8, safety in the event of an emergency is enhanced.

With the control described above, in this example, the powered cart 1 is moved by pushing the hand bar 2 with the hand in the same way as a normal cart, and the extremely light weight of the cart is being pushed. This means that you can transport your belongings in the same way.

Next, a second embodiment shown in FIG. 9 will be described. In this second embodiment, in addition to the functions of the first embodiment described above, the motorized cart 1 is stopped by the same process as when the stop switch 22 is turned on when the hand bar 2 is released. This feature has been added with the function of Next, it will be explained in detail.

First, as shown in FIG. 9, a metal touch plate 24 is provided on the hand bar 2 of the powered truck 1 so as to wrap around the side surface thereof. This touch plate 24 is connected to the CPU 8 via a sense amplifier 26 made of a C-MOSIC or the like for amplifying the weak voltage that is generated. Note that the other configurations are the same as those in the first embodiment, so explanations will be omitted. (In order to simplify the explanation, FIG. 9 shows only the part mainly containing the sense amplifier 26, and other parts are omitted.) Next, the operation and effect will be explained based on the flowchart shown in FIG. Explain. First, when the touch plate 24 is removed, the CPU 8 detects the loss of the signal from the sense amplifier 26 and generates an interrupt. Then, the routine shown in FIG. 10 starts, and first, in step 300, an interrupt caused by turning on the touch plate 24 is permitted, and in step 301, the timer is turned on, and then the process proceeds to step 302.

Step 302 is a timer routine for determining the control cycle, and since the timer is initially turned on in step 301, the process immediately proceeds to step 303, where the drive wheels 3 and 4 are turned on.
It is determined whether the current rotational speeds of both of the brakes 20 and 27 are within a speed range in which the brakes 20 and 27 can be turned on. If this is YES, proceed to step 305, and if NO, proceed to step 304, where the drive wheel 3
After outputting an acceleration corresponding to the current rotational speed of the drive wheels 4, the process returns to step 302.

The map referred to in steps 303 and 304 is the same map shown in FIG. 8 as used in the interrupt processing by the stop switch 22 described above.

On the other hand, if the determination in step 303 is YES, the process proceeds to step 305, where the interrupt routine caused by turning on the touch plate 24 is masked, and the process proceeds to step 306, where the drive control devices 13, 15 are turned off,
After turning on the brakes 20 and 27 and resetting the timer in step 307, the process returns to step 100 of the main routine shown in FIG.

The above processing describes the interrupt processing when the touch plate 24 is removed.
Even if the touch plate 24 is released, if the touch plate 24 is grasped again before the motorized truck 1 stops, it is necessary to return to normal processing.

Therefore, in this example, in addition to the above-mentioned interrupt routine, an interrupt routine for turning on the touch plate 24 shown in FIG. 11 is provided.

To explain this, touch plate 24
When a hand touches , an interrupt occurs and the routine shown in FIG. 11 starts. In this routine, at step 400, the interrupt routine is first masked so that no interrupt occurs due to the touch plate 24 being turned on during the processing of this routine, and then at step 401, the timer is reset, and then the timer is reset as shown in FIG. The program now advances to step 103 of the main routine. That is, normal acceleration or deceleration processing is performed by moving the processing to step 103 of the main routine.

In this way, in this second embodiment, when the hand is removed from the push bar 2, the motorized cart 1 can be automatically stopped in the same way as when the stop switch 22 is operated.

Therefore, whenever the hand bar 2 is removed from the hand, the stop processing is performed, which further improves safety. Note that the other processes are the same as those in the first embodiment, so the explanation thereof will be omitted.

Next, a third embodiment will be described. In this third embodiment, whereas in the first embodiment the accelerations of the drive wheels 3 and 4 were calculated from the rotational speeds of the drive wheels 3 and 4, (in the first embodiment, in step 107 of the main routine) , the acceleration is calculated from the difference between the previous speed and the current sampling speed) The acceleration of the drive wheels 3 and 4 is directly determined using A/D converters 31 and 32, and predetermined control is performed based on this. It's summery.

Therefore, in this third embodiment, A/D converters 31 and 32 and accelerometers 29 and 30 are newly provided to the control circuit 25 as shown in FIG. For A/
D converters 31 and 32 and accelerometers 29 and 3
0 and CPU 8 are shown, and other circuits are omitted. ) Also, in step 107 of the main routine shown in FIG. 4, acceleration is input from the A/D converters 31 and 32, as shown in FIG.

In this way, in this third embodiment, the acceleration is changed to A/
Since it is determined by hardware using the D converters 31 and 32, there is no need for calculation time to determine the acceleration, and therefore data with higher accuracy can be obtained faster and the accuracy of control can be improved. There is.

(Effects of the Invention) As detailed above, in the present invention, the force applied to the hand bar is measured and the drive motor is driven and controlled based on this applied force. It has the excellent feature that it does not require any of the troubles associated with driving a motorized cart, and can be operated as if lightly pushing a light handcart.

Therefore, it does not require any skill to operate, and anyone can operate it easily, and there are no problems such as the motorized cart flying out or stopping suddenly due to unfamiliar operation.

Furthermore, the force applied to the powered cart by the worker is individually measured at at least two positions, and the acceleration/deceleration is determined from the measured values to drive the separately provided drive sources. Therefore, it is characterized in that it is extremely easy to steer the powered truck in the left and right directions.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1 is a block diagram showing a first embodiment of the control circuit;
FIG. 2 is a perspective view showing the powered truck, and FIG. 3 is an explanatory diagram showing patterns of each running state of the powered truck based on signals from the strain gauge and the rotational speed of the drive wheels.
Figure 4 is a flowchart showing the first embodiment of the main routine set in the ROM, Figure 5 is a diagram showing the relationship between the stress applied to the hand bar and the acceleration determined by it, and Figure 6 is a diagram showing the relationship between the stress applied to the hand bar and the acceleration determined by it. A diagram for determining the acceleration at the speed of each drive wheel in order to gently stop the powered truck when the stress on the vehicle becomes 0, FIG. 7 is a flowchart showing an interrupt routine when the stop switch is turned on, and FIG.
The figure is a diagram showing the braking conditions when stopping the powered truck, Figure 9 is a block diagram showing the main parts of the control circuit in the second embodiment, and Figure 10 is the touch diagram in the second embodiment. FIG. 11 is a flowchart showing the interrupt routine due to plate-on, FIG. 11 is a flowchart showing the interrupt routine due to touch plate-off, FIG. 12 is a block diagram showing the main part of the control circuit in the third embodiment, and FIG. 13 is a flowchart showing the interrupt routine due to touch plate-off. It is a flowchart showing changes in the main routine in the third embodiment. 1...Motorized trolley, 2...Hand bar, 3, 4
... Drive wheel, 5 ... Strain gauge, 6, 7, 14, 2
8, 31, 32...A/D converter, 8...
CPU, 9...RAM, 10...ROM, 13,1
5... Drive control device, 16, 18... Drive motor, 17, 19... Speed sensor, 20, 27...
Brake, 21...Start switch, 22...
Stop switch, 23...Emergency stop switch, 24
...Touch plate, 25...Control circuit, 26...
...Sense amplifier, 29,30...Accelerometer.

Claims (1)

[Claims] 1 At least two separate drive sources consisting of motors
A drive control device for a powered trolley having at least two
A measuring device for individually measuring at a location;
A calculation device for individually calculating acceleration/deceleration according to each measurement value from this measurement device; and a calculation device for individually driving the motors based on each calculation value from this calculation device. A drive control device for a powered trolley, characterized in that it is comprised of a drive device.