JPH044186B2 - - 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.

Conventionally, various types of operating devices for powered trolleys have been put into practical use. These devices include those that use a joy stick to control the speed and direction of movement of the powered cart, and those that have an operating grip similar to the accelerator on a motorcycle, etc., and control the running speed by rotating it. There are things to do.

(Problem to be Solved by the Invention) However, with conventional devices that use joysticks or rotate operating grips, they require considerable skill to operate, and anyone can easily operate them. I had a problem 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 a measuring device for individually measuring the force applied to the trolley by the worker, and an arithmetic device that adds and subtracts values, calculates acceleration from the added value, and calculates angular acceleration from the subtracted value; a driving device for driving a drive motor based on the acceleration; and a steering device based on the angular acceleration. The present invention is characterized in that a drive control device for a powered truck is constituted by a steering control device for rotating a motor.

(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, and a hand bar 2 is attached to a side surface 1a of the powered trolley 1 via a support rod 2a. On the other hand, two driving wheels 3 are provided at the rear of the lower surface of the powered truck 1, and one steering wheel 4 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 will be explained based on FIG. 1. first,
Strain gauges 5, 5 are provided on the two support rods 2a mentioned above, respectively. This is made of, for example, a resistance wire strain gauge, and is similar to the support rod 2a.
It is attached to. Note that in this example, the strain gauges 5,
5, the support rod 2a is given some flexibility.

Signals from the strain gauges 5, 5 are input to the CPU 8 via A/D converters 6, 7, respectively. The CPU 8 is a normal 8-bit microcomputer, which includes RAM.
9 and ROM10 are connected. and,
The ROM 10 contains a 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, is connected to the drive motor 1.
The other D/A converter 12 is connected to a steering control device 15 for driving a steering motor 18 .

The drive motor 16 is a normal DC type servo motor, and is driven and controlled by the output current from the drive control device 13. The drive motor 16 is provided with two drive wheels 3, 3, a brake 20, and a speed sensor 17.

The speed sensor 17 is composed of a tachometer generator or the like, and is designed to output a voltage proportional to the rotational speed of the drive motor 16. The output signal from this speed sensor 17 is A/
The analog signal is converted into a digital signal by the D converter 14 and then input to the CPU 8.

The brake 20 is for stopping the rotation of the motor 8, and its ON/OFF state is controlled by signals from the CPU 8 and the emergency stop switch 23.

The steering motor 18 is a normal DC type servo motor, and is driven and controlled by the output current from the steering control device 15. A steering wheel 4 is rotatably provided on the steering shaft 18a of the steering motor 18 at right angles to the axial direction of the steering wheel 4, and a steering angle detector 19 is further provided on the steering shaft 18a. This steering angle detector 19 is for detecting the rotation angle of the steering shaft 18a, and detects the rotation angle of the steering shaft 18a rotated by the output current from the steering control device 15, and detects the rotation angle of the steering shaft 18a. It is designed to perform loop control.

Next, stop switch 22, emergency stop switch 2
3. The start switch 21 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. When turned on, current is supplied to each circuit and the CPU 8 is reset. A predetermined program is now being executed.

The stop switch 22 is for applying a brake to the motorized truck 1, and when it is turned on, an interrupt occurs 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, drive control device 13, and brake 20. When this switch is turned on, it immediately turns off the drive control device 13 and activates the brake 20. It also has the function of holding the CPU8. This emergency stop switch 23 can apply the brake directly without going through the CPU 8, thereby increasing safety in an emergency.

Next, the action and effect will be explained. first,
The basic control pattern in this example will be explained based on FIG. 3 A and B.

First, the control pattern of the drive motor 16 will be explained with reference to FIG.
When the sum of the outputs from the motor vehicle 1 is 0, it is determined that a stop condition has been reached, and the acceleration and vehicle speed are set to 0 to stop the motorized truck 1.

Next, as a second pattern, the sum of the outputs from the left and right strain gauges 5, 5 is + (i.e.,
When the hand bar 2 is pushed forward. ) and the vehicle speed is 0, it is determined that the start condition is met,
Set the acceleration instruction to +. For this reason, the powered trolley 1
The speed of will gradually increase from 0.

As a third pattern, when the powered truck 1 is traveling at a predetermined speed, the left and right strain gauges 5,
When the sum of the outputs from 5 reaches 0, a slight deceleration instruction is given. 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 sum of the outputs from the left and right strain gauges 5, 5 becomes + while the powered trolley 1 is running at a predetermined speed, it is determined that an acceleration condition exists and an acceleration instruction is given. It's becoming like that.

As the fifth pattern, when the sum of the outputs from the left and right strain gauges 5, 5 becomes - while the vehicle is running at a predetermined speed (i.e., when the hand bar 2 is pulled backward) , the system determines that a deceleration condition is met and decelerates.

Next, the control pattern of the steering motor 18 will be explained with reference to FIG. When is 0, it is determined that the straight running condition is met, and the angular acceleration instruction to the steering control device 15 is set to 0. Therefore, the steering angle of the steered wheels 4 is set to 0 degrees, and the powered truck 1 moves straight.

Next, as a second pattern, when the steering wheel 4 is rotating clockwise and the difference between the outputs from the left and right strain gauges 3 is positive, the acceleration condition (that is, the rotation angle to the right is The angular acceleration instruction to the steering control device 15 is set to +. Therefore, the rotation angle of the steered wheels 4 to the right becomes even larger, and clockwise rotation is promoted.

Next, as a third pattern, when the steering wheel 4 is rotating clockwise and the difference between the outputs from the left and right strain gauges 3 is 0, it is determined that the rotation is steady, and the steering control device 15 Make the angular acceleration instruction slightly negative. For this reason, the steering wheel 4
The steering angle gradually decreases.

Next, as a fourth pattern, when the steering wheel 4 is rotating clockwise and the difference between the outputs from the left and right strain gauges 3 is negative, the reduced angular velocity condition (based on the rotation angle of the steering wheel 4) is applied. condition), and set the angular acceleration instruction to a negative value. Therefore, the steering angle of the steered wheels 4 is turned in the opposite direction.

The above is the basic speed instruction and steering angle control pattern in this example. However, in the above explanation, the backward traveling control of the powered trolley 1, the forward left rotation steering control,
Since the reverse right rotation steering control and the reverse left rotation steering control are the same, they are omitted.

Next, specific details of the control will be explained based on the flowcharts shown in FIGS. 4A and 4B and FIG. 5.

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, initialization of each part is performed, and the brake 20 is turned on to prevent the motorized cart 1 from starting to run carelessly.

When this is completed, in step 101 the process waits for input from the start switch 21. Then, when the start switch 21 is turned on, the step
Proceeding to step 102, the brake 20 is turned off to enable driving, and the drive control device 13 is turned on.

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 setting 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 proceeds to step 104, where data is input from the strain gauge 5 provided on the left support rod 2a (in the upper part of the figure in FIG. 1), and then the process proceeds to step 105. This time, data is input from the strain gauge 5 provided on the right support rod 2a (lower in FIG. 1). Each of these data is converted from analog to digital by A/D converters 6 and 7, and then input to the CPU 8, where each data is converted into stress based on a predetermined program.

When the processing in step 105 is completed, step
The process proceeds to step 106, where the vehicle speed is input from the speed sensor 17, and then the process 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 velocity per unit time.

Once this acceleration has been calculated, the process proceeds to step 108, where it is determined whether the vehicle speed is 0 or not. If the vehicle speed is 0, the process proceeds to step 109, and if the vehicle speed is not 0, the process proceeds to step 112. In both step 109 and step 112, it is determined whether the sum of the stresses detected by the strain gauges 5, 5 is 0 or a 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 assumed to be 0 within a range where the force applied to the strain gauges 5, 5 is extremely small.

If the determinations at steps 109 and 112 are NO, the process advances to step 111, where the acceleration/deceleration corresponding to the sum of stresses is read out from the map set in the ROM 10, and based on this, the drive motor is adjusted.
6.

Here, the ROM referenced in this step 113
The map in 10 is as shown in Figure 5, where the range of low stress is treated as a dead zone and the acceleration is reduced to 0.
When a stress exceeding a predetermined value is applied, an acceleration or deceleration approximately proportional to this stress is indicated. (In other words, data having such a predetermined correspondence relationship is written as data in the ROM 18.) If the determination at step 109 is YES, the process advances to step 110 and the drive motor is The acceleration instruction for step 16 is set to 0 before proceeding to step 114.

On the other hand, if the judgment in step 112 is YES, the process advances to step 113, where the current powered truck 1
The acceleration/deceleration according to the vehicle speed is read out from a map set in the ROM 10, and the rotation speed of the drive motor 16 is controlled based on this.

Here, the ROM referenced in this step 113
The map in 10 is as shown in FIG. 6, and is designed to indicate deceleration approximately proportional to speed. However, the deceleration instruction in step 113 is given by the operator when the vehicle is moving.
This is equivalent to stopping pushing the wheel, so the deceleration is extremely gradual, similar to the gradual deceleration of a light truck. When the process at step 113 is completed, the process proceeds to step 114.

In step 114, it is determined whether the steering angle of the steered wheels 4 is 0 or not. Here, if the steering angle is not 0, the process proceeds to step 118, and if the steering angle is 0, the process proceeds to step 115.

In both step 115 and step 118, it is determined whether the difference in stress detected by the strain gauges 5, 5 is 0 or in a dead zone. Here, as shown in FIG. 9, the dead zone is a range in which the difference in stress detected by the strain gauges 5 is considered to be zero within a range where the difference is extremely small.

The judgment at step 115 and step 118 is NO.
In both cases, the process proceeds to step 117, where the angular velocity corresponding to the difference in stress is read from the map set in the ROM 10, and the rotation angle of the steering motor 18 is controlled based on this. .

Here, ROM10 referred to in step 117
The map inside is as shown in Figure 9,
The range where the difference in stress detected from the left and right strain gauges 5, 5 is small is a dead zone and the angular acceleration is set to 0, and when the difference in stress reaches a predetermined value or more, the angular acceleration is approximately proportional to the magnitude of this difference. It has come to be used as an instruction.

If the determination at step 115 is YES, the process advances to step 116, where the steering motor 18 is
After setting the angular acceleration instruction to 0 to 0, the process returns to step 103.

On the other hand, if the judgment in step 118 is YES, the process proceeds to step 119, where the angular velocity corresponding to the current steering angle of the steering wheels 4 is read out from the map set in the ROM 10, and based on this, the steering motor 18 rotation angles are controlled.

Here, the ROM referenced in this step 119
The inner map is as shown in FIG. 10, and is designed to indicate a negative angular velocity that is approximately proportional to the steering angle. Therefore, powered trolley 1
When the vehicle is turning, if the force applied to the hand bar 2 is approximately the same on both the left and right sides, the steering angle of the steering wheels 4 will automatically gradually return to the straight-ahead state.

Now, to explain the correspondence between the control pattern shown in FIG. 3A and the flowchart shown in FIG. 4, when the control pattern shown in FIG.
After passing through step 110, the process proceeds to step 114.

At the start shown in the second pattern,
The process proceeds to step 114 via step 108, step 109, and step 111.

In the running state shown in the third pattern, steps 108, 112 and 113 are performed.
The program then proceeds to step 114.

During acceleration control shown in the fourth pattern,
The process proceeds to step 114 via step 108, step 112, and step 111.

During deceleration control shown in the fifth pattern,
The process proceeds to step 114 via step 108, step 112, and step 111.

Next, to explain the correspondence between the control pattern shown in FIG. 3B and the flowchart shown in FIG. The process now returns to step 103.

When controlling the angle of rotation in the clockwise rotation direction shown in the second pattern, the process proceeds to step 114, step 118, and step 117, or steps 114, step 115, step 117, and then returns to step 103. .

In the steady rotation state shown in the third pattern, steps 114, 118, and 119 are performed.
The process then returns to step 103.

When attempting to restore the angular decrease speed shown in the fourth pattern, that is, the clockwise rotation, the process proceeds through step 114, step 118, step 117, and then returns to step 103.

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

Next, control when the emergency stop switch 23 or the stop switch 22 is operated will be explained. first,
When the stop switch 22 is turned on, an interrupt occurs, and the control of the main routine shown in FIG. 4 is temporarily interrupted, and the control 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 this interrupt processing is first started.

Upon completion of step 201, the process immediately proceeds from step 202 to step 203, where it is determined whether the speed of the vehicle is 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 running speed of the powered trolley 1 is in the range from -V1 to V1, it is determined that the speed is such that even if the brake is applied, it will not result in sudden braking, and the brake 20 is turned on and the brake is applied. It's becoming like that.

On the other hand, if the running speed of the powered trolley 1 is V1 or higher or -V1 or lower, it is determined that the speed is such that applying the brake would result in sudden braking, and the acceleration or deceleration corresponding to the vehicle speed is instructed. I'm starting to do that. That is, for example, when the vehicle speed 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 speed is within a safe speed range even if the brake 20 is turned on, so step 203 is executed.
Proceed to step 205 to turn off the drive control device 13 and turn on the brake 20, then proceed to step 205.
After the timer is reset in step 206, the process returns to step 101 of the main routine shown in FIG.

On the other hand, if the determination in step 203 is NO, that is, if the vehicle speed is not within the speed range where the brake can be turned on, the acceleration/deceleration corresponding to the vehicle speed is read out from the ROM 10 and instructed. . When the process in step 204 is completed, the process returns to step 202 and the same process is repeated until the vehicle speed reaches a speed range where the brakes can be turned on.When the vehicle speed reaches the speed range where the brakes can be turned on, , the program proceeds to steps 205 and 206, turns on the brake, and returns to the main routine, as described above.

Next, control when the emergency stop switch 23 is turned on will be explained. When this emergency stop switch 23 is turned on, the drive control device 13 is directly turned off by this switch, and the brake 2
0 is turned on and the CPU 8 is placed in a hold state. 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, thereby pushing the extremely light weight cart. This means that you can transport your belongings in the same conditions as you would if you were there.

Next, a second example will be described. This second
In this embodiment, in addition to the functions of the first embodiment described above, when the hand bar 2 is released, the stop switch 22 is activated.
A function is added to stop the motorized truck 1 by the same process as when the switch is turned on. Next, it will be explained in detail.

First, as shown in FIG. 11, 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. (11th
In order to simplify the explanation, only the part mainly containing the sense amplifier 26 is shown in the figure, and other parts are omitted. ) Next, the functions and effects will be explained based on FIG. 12. 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 as shown in FIG. 12.

Then, the routine shown in FIG. 12 starts, and first, in step 300, the touch plate 2 is
6 ON, the interrupt routine is enabled, the timer is turned on in step 300, and the process proceeds to step 302.

Step 302 is a timer routine for determining the control cycle, but since the timer is initially turned on in step 301, the process immediately proceeds to step 303, where the current vehicle speed is determined by the brake 20. A determination is made as to whether or not the speed is within a speed range where the switch can be turned on. And this is YES
If so, the process proceeds to step 305; if NO, the process proceeds to step 304, outputs the acceleration according to the current speed of the vehicle, and then 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 device 13 is turned off and the brake 20 is turned on. After 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 powered 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 caused by turning on the touch plate 24 shown in FIG. 13 is provided.

To explain this, touch plate 24
When a hand touches , an interrupt occurs and the routine shown in FIG. 13 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 processing of this routine, and then at step 401, the timer is reset, and the main operation shown in FIG. The routine now advances to step 103. That is, by moving the process to step 103, normal acceleration or deceleration processing is performed.

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

For this reason, 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.

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

For this reason, it has the advantageous feature that anyone can operate it easily without requiring any skill, and there is no problem such as when the powered trolley suddenly jumps out or suddenly stops due to unfamiliar operation. be.

Furthermore, the force applied to the powered cart by the worker is measured at at least two locations, the acceleration is calculated from the addition of these measured values, and the angular acceleration for steering the cart is calculated from the subtracted value of the measured values. It also has an excellent feature in that it is extremely easy to steer the powered truck by having a configuration that requires this.

[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;
Figure 2 is a perspective view showing the powered truck, Figure 3 (a) is an explanatory diagram showing the patterns of each running state of the powered truck depending on the sum of signals from the left and right strain gauges and the vehicle speed, and Figure 3 (b) is An explanatory diagram showing the steering pattern of the steered wheels based on the value of the difference between the signals from the left and right strain gauges, Fig. 4 A and B are a flowchart showing the first embodiment of the main routine set in the ROM, and Fig. 5 is a flowchart showing the first embodiment of the main routine set in the ROM. A diagram showing the relationship between the sum of stress applied to the hand bar and the acceleration determined by it, Figure 6 is a diagram showing the relationship between the sum of stress applied to the hand bar and the acceleration determined by it. A diagram for determining acceleration at vehicle speed, FIG. 7 is a flowchart showing stop control when the stop switch is turned on,
Figure 8 is a diagram showing the braking conditions when stopping a powered truck, and Figure 9 is a diagram showing the difference in stress detected by the left and right touch plates and the angular acceleration instruction to the steering motor determined by this. 10 is a diagram showing the relationship between the steering angle and the angular acceleration instruction when the steering wheel is being steered and the difference in stress applied to the target plate becomes zero. The figure is a block diagram showing the main part of the control circuit in the second embodiment, Figure 12 is a flowchart showing the interrupt routine caused by touch plate off, and Figure 13 is the interrupt caused by touch plate on in the second embodiment. 3 is a flowchart showing a routine. 1...Motorized trolley, 2...Hand bar, 3...Drive wheel, 4...Steering wheel, 5...Strain gauge, 6...
A/D converter, 7...A/D converter, 8...CPU, 9...RAM, 10...ROM,
11... D/A converter, 12... D/A converter, 13... Drive control device, 14...
A/D converter, 15...Steering control device, 1
6... Drive motor, 17... Speed sensor, 18
...Steering motor, 19...Steering detector, 20...
...Brake, 21...Start switch, 22...
...Stop switch, 23...Emergency stop switch, 2
4...Touch plate, 25...Control circuit, 26
...Sense amplifier.

Claims (1)

[Claims] 1. A drive control device for a powered trolley, which has a drive motor for driving drive wheels and a steering motor for rotating a steering wheel by a predetermined angle, which controls the force applied to the trolley by an operator at least 2 times. A measuring device for measuring each location individually, a calculating device that adds and subtracts each measurement value from this measuring device, calculates acceleration from the added value, and calculates angular acceleration from the subtracted value, and this calculation It is characterized by being comprised of a drive device for driving the drive motor based on the acceleration calculated by the device, and a steering control device for rotating the steering motor based on the angular acceleration. A drive control device for a powered trolley.