CN1113280C - Automatic guide method for vehicles - Google Patents

Abstract

The automatic guidance of the vehicle relates to a method of automatic guidance for the operation of the unmanned vehicle. The vehicle is guided by the guidance path preset on the ground of the factory and Lunku, etc., and loads and handles various loads in a fully automatic manner. , more specifically relates to a fully automatic guidance method with a route search function and an anti-deviation function, so that a vehicle placed at the starting position of operation and whose magnetic sensor deviates from the guidance path within a certain range, or during normal operation due A car that suddenly deviates from its course for some reason is restored to the guided path by searching and finding the tape.

Description

Automated Guidance Methods for Vehicles

field of invention

The present invention relates to a method for automatically guiding the operation of an unmanned vehicle, which is guided by a guiding path preset on the ground in factories, warehouses, etc., and loads and handles various loads in a fully automatic manner; more specifically It relates to an automatic guidance method with a route search function and an anti-deviation function, so that a vehicle that is placed in an operation start position and whose magnetic sensor deviates from the guidance path within a certain limit, or suddenly deviates from the route due to some reasons during normal operation The car is restored to the guided path by searching and finding the tape.

Background technique

Various automated guided vehicles (often abbreviated as AGVs) have been developed and used in practice.

For example, Japanese Registered Patent No. 3013716 discloses an unmanned magnetically guided vehicle that runs automatically along a closed loop formed by a magnetic tape.

The above-mentioned unmanned magnetic guidance vehicle shows a high level of technology development and practice. However, because this car uses a system that uses its internal magnetic sensor to detect the magnetism (magnetic field) made of magnetic tape to guide the vehicle. If the car is in its initial position with its magnetic sensor outside the effective range of the magnetic field generated by the magnetic tape, the car cannot be started. In this case, the person in charge had to look under the car and manually adjust the position of the car to align the sensor and tape, which caused a considerable delay before starting.

Also, when the vehicle is off course due to an obstacle or unexpected external force on the guide path, the vehicle must be manually restored to the guide path and the restart button must be manually pressed within the time required to resume operation to resume operation. Such manual operation reduces the efficiency of such vehicles.

Contents of the invention

It is an object of the present invention to provide a method of automatic guidance in which a vehicle is placed with its sensor outside the effective range of the magnetic field of the guide belt, as long as its sensor is close enough to the guide belt to pass within a predetermined period of time If the automatic search (route search function) can detect the guide belt, it can be started to run normally and repositioned; moreover, in this method, through the automatic search (anti-deviation function) of the guide path, it can make a vehicle in normal operation. Vehicles that suddenly deviate from the route during operation are restored to the path, thereby improving the efficiency of such guided vehicles.

The second object of the present invention is to provide a guiding method. In this method, after a vehicle presses the start button (start operation), it fails to find the guide belt within the time of the preset route search function, or, When a vehicle deviates from the route for some reason and fails to return to the route within the preset anti-deviation function time, the operation of the vehicle is suspended to prevent accidents.

The automatic guiding method of a magnetically guided vehicle according to the present invention is operated as follows, the vehicle has a drive wheel, a magnetic sensor, which detects the magnetic field generated by the guiding path formed by the magnetic tape placed on the ground along the running route of the vehicle. Magnetic, a driving device and a driving device controlled by a control device that processes the signals detected by said sensor, the method is characterized in that:

(a) at the beginning of the operation, the vehicle is controlled by turning said sensor left and right to search said guiding path;

(b) if the guide path cannot be found through the above control process (a), as a second step, the vehicle is subjected to a controlled low-speed motion of turning the sensor fully in a certain direction to search for the guide path, for a predetermined period of time, and, if the guiding path is still not found, turning the driving device completely in the opposite direction and continuing to move at a low speed for twice the preset time of the previous turning;

(c) if said guided path is found by said control process (a) or (b), said vehicle is controlled to accelerate to normal speed along said guided path to resume operation; and

(d) stopping operation of the vehicle if the guided path is not found within the preset time by the control process (a) or (b).

According to another guiding method of the present invention for a magnetically guided vehicle, the vehicle has a drive wheel, a magnetic sensor that detects the magnetism generated by a guiding path formed by a magnetic tape or the like placed on the ground along the running route of the vehicle, A driving device, and a driving device controlled by a control device, the control device processing the signal detected by the sensor, the method is characterized in that:

(a) If the vehicle deviates from the route during operation, first shift the gear of the vehicle to a low speed, determine the direction of deviation, turn the driving device in the direction opposite to the deviation, and carry out the operation within a predetermined period of time the search of the guided path, and when the vehicle is restored to the guided path, the vehicle is accelerated to normal speed to resume operation; and

(b) If the vehicle cannot return to the guided path through the control process (a) within the preset time, the operation of the vehicle is terminated.

According to this automatic guidance method, if a vehicle is constituted by a magnetic guidance driving-driving unit, the unit includes a driving wheel, a magnet for detecting a guiding path formed by a magnetic tape, and is installed for driving with the driving wheel a magnetic sensor, a driving device and a steering device that enable the driving wheels to be automatically controlled by a control device that processes the signals detected by the sensors, and a driving/driving device with four wheels per corner Then, when the car is operated and started, it is controlled at first, so that the sensor is turned left and right together with the driving wheel through the driving device, so as to search for the guiding path while the car is parked.

On the other hand, according to this automatic guiding method, when a vehicle is composed of a pair of driving wheels on both sides of the lower middle part of the chassis, a magnetic sensor used to detect the guiding path formed by the magnetic tape at the front of the trolley, a magnetic sensor that makes each driving wheel When the driving device that can be automatically controlled by a control device for processing signals from the sensor and a driving device that differentially drives the drive wheels through the driving device automatically controlled by the control device, the vehicle is started by It is controlled so that the sensor is rotated left and right to differentially drive the pair of drive wheels by the steering device to search for a guide path.

The vehicle shown in Figures 1-3 with a single drive wheel can be constructed from a single drive and steering unit and the controls can also be simplified. However, to ensure smooth operation, the front wheels of the block should be universal casters, while the rear wheels should be fixed casters, which makes it difficult to automatically control (drive) the car backwards. On the other hand, a vehicle with two drive wheels as shown in Figures 9 and 10 would require a device to drive and steer each drive wheel so that synchronous drive is controlled by differential drive although all sheaves could be common castors and turning controls are more complicated. This makes it easy to automatically control (drive) forward and backward movement, and it should be noted that this type of vehicle is very suitable for moving along straight roads as well as moving along curved roads.

In the present invention, the maximum preset time for performing the route search function or the deviation preventing function can be set to any value.

Since the operation of the guided vehicle is initiated, say, by pressing a start button, the software in the control box (control unit) is programmed so that the vehicle will operate unmanned until the stop button is pressed .

When the start button is pressed, as a first step, the steering unit turns the sensor left and right. If through this process, the sensor enters the guide path area, the sensor sends out a detection signal, and the vehicle immediately starts normal operation. Otherwise, the control device executes the second step: the driving device is turned left (or right) completely, and the driving device moves the car by turning slowly, so as to search for the position of the guiding path within a preset period of time. If the guide path cannot be found through this operation, the driving device turns completely in the opposite direction (ie to the right), similarly moving the car by turning slowly to search for the position of the guide path within a preset period of time. When the guide path is detected, the car is accelerated to normal high speed running along the guide path. If a guided route is not found during a preset time, the vehicle's movement is stopped immediately (route search function).

On the other hand, when the vehicle suddenly deviates from the course during normal operation, the directional deviation is immediately determined by calculations by the control means, based on data showing changes in the relative position of the sensors of the guiding path with respect to the point of deviation. Then, the car turns the steering gear in the opposite direction of the deviation direction and shifts to a low gear to search for the guidance path. Since the vehicle is indeed back on the guiding path at the moment when the sensor detects the guiding path, the vehicle is accelerated to normal high speed running along the guiding path. However, if the guided path cannot be detected within a preset time, the running of the car is immediately stopped (deviating function).

The automatic guiding method of the present invention can also be adopted by the following types of guided vehicles:

1) An electromagnetic guided vehicle, which is guided by a sensor detecting a magnetic field formed around a wire that is placed on the ground or under the ground and has a current passing through it.

2) A light-guided vehicle, which uses optical sensors to detect guide belts placed on the ground for guidance.

3) A magnetically permeable vehicle, which is guided by magnetic sensors detecting magnetic materials placed on or under the ground.

According to the automatic guiding method of the guided vehicle of the present invention, when a vehicle is placed in the initial position, its sensor is outside the guiding path, and it can be started by automatically detecting the guiding path, which means that the vehicle only needs to be roughly positioned relative to the guiding path, As a result, the start-up preparation time is shorter and the efficiency is higher.

Furthermore, in the event that the vehicle accidentally deviates from the guided path, the vehicle can be automatically returned to the guided path without stopping the operation, which also results in reduced time loss and improved operating efficiency.

Description of drawings

Fig. 1 is a three-dimensional view showing the structure of the magnetic guide car in a disassembled state;

Figure 2 is a plan view of the drive/driving unit;

Fig. 3 is a side view of the driving/driving unit;

Fig. 4 is a schematic plan view showing the search range of the sensor rotating left and right to scan the magnetic tape;

Fig. 5 is a schematic plan view of searching the magnetic tape position during low-speed operation;

Fig. 6 is a schematic plan view of searching the magnetic tape position during low-speed operation;

Fig. 7 is a schematic plan view of the vehicle returning to the guiding path after deviating from the search tape;

Fig. 8 is a process block diagram explaining the automatic guidance method;

Figure 9 is a bottom view of an example vehicle with two drive wheels and four universal casters; and

Figure 10 is a bottom view of an example vehicle with two drive wheels and two universal casters.

Detailed ways

Embodiments of the present invention are described below with reference to the accompanying drawings.

The overall structure of the automatic guided vehicle (AGV) shown in Figures 1-3 is similar to the vehicle structure disclosed in Japanese Patent No. 3013716, and will now be briefly described.

The AGV comprises a drive/steering unit 3 of the magnetically guided type, which has a drive unit 5 for driving wheels 6, and a steering unit 4 for driving wheels 6, and a trolley with a chassis 16 with wheels at the corners 12. The drive is controlled by a control device 8 which processes signals from a magnetic sensor 7 which detects the magnetism produced by the guide path formed by the magnetic tape 10 . The steering/drive unit 3 is attached under the chassis. As shown in FIG. 3 , the magnetic sensor 7 is attached to the front of the support member of the driving wheel 6 with a bracket 17 so that the magnetic sensor 7 rotates together with the driving wheel 6 . The magnetic force sensor 7 is positioned at the right half of the horizontal bar (Fig. 4). The magnetic sensor 7 and the control device (control box) 8 are connected by a cable 18 .

Racks 13 are mounted on the chassis 16 of the trolley 12 to carry loads, if necessary. The attached plate 2 of the driving/driving unit 3 is placed under the chassis 16, and is fixed on the attached seat 14 with fastening bolts. 12 front wheels of tackle are universal casters, and trailing wheels are fixed casters. A control device (control box) 8 that processes signals from the magnetic sensor 7 controls a driving motor as a driving device power source for the driving wheels 6 and a driving device (such as a steering motor) 4 as a driving device energy source for the driving wheels 6 . The chassis 16 and the shelf 13 are composed of resin-coated steel pipes coupled together with joints.

The connector 9 is used to connect the driving device (such as a driving motor) 4 and the driving device (such as a driving motor) 5 with a power battery (not shown) installed on the chassis 16 . A control box 8 for implementing the automatic control process of the driving/driving unit 3 is attached to the rear and lower part of the accessory plate 2 . The automatic guidance method software process in the automatic control device in the control box 8 is as shown in Figure 8.

Fig. 4 shows the interval W, after pressing the start button to start the vehicle, as the first step of the route search function, when the vehicle itself is still stationary, the magnetic sensor 7 and the drive wheel 6 are rotated left and right together, The steering device 4 of the driving/steering unit 3 is able to detect the magnetic field generated by the magnetic tape 10 in this region. The magnetic sensor 7 is arranged on the left side of the driving wheel 6, and the driving wheel 6 is arranged in the middle of the width of the driving/steering unit 3, or more precisely, within 75mm (approximately the right half) from the right end, to minimize the driving wheel 6 Possibility of stepping on the tape 10. The width of the range W in which the magnetic sensor 7 can detect the magnetic field of the magnetic tape 10 by rotating left and right is about 210 mm.

Figure 5 shows the vehicle (drive/steering unit 3) and the magnetic sensor 7, as an example, they have moved out of the tape 10 to the right, the position of the tape 10 cannot be determined by turning the magnetic sensor 7 left and right (first step of control) , now enter the second step of control. In the second step of control under the above situation, the driving/driving unit 3 turns the driving wheel 6 completely to the left, and starts at a low speed of 4 m/min to search for the position of the magnetic tape 10 for a preset period of time (the present embodiment 20 seconds in medium). In this case, it is obvious that tape 10 will be found soon.

Figure 6 shows the situation where the magnetic sensor 7 and the vehicle (drive/steering unit 3) are located to the left of the tape 10 and in the second step of the control. With the drive wheel turning completely to the left as shown in FIG. 5 (shown in dashed lines), it is clear that the magnetic tape 10 cannot be detected within the search preset time. The second step of control then turns the drive wheels 6 fully to the right and lets the vehicle run the search tape 10 (shown in solid line) at low speed for twice the time of the previous test (40 seconds in this example), This will find that the probability of the vehicle and the magnetic sensor 7 reaching the magnetic tape 10 and sending out a detection signal is quite high.

As mentioned above, in the first step of control, just after pressing the start button to start the operation of the AGV, the AGV may be in any initial position, only by moving the magnetic sensor 7 left and right to search for the guiding path, and the car itself does not move. If no guided path is found in this step, control passes to a second step where the search is performed by first turning left at a low speed and then, if no guided path is found, by turning right at a low speed, thereby establishing a fairly wide search intervals and high success rate in finding guided paths. If, despite all the above-mentioned measures, the magnetic sensor 7 cannot find the guide path (tape), this is defined as an abnormal situation. Operations on the vehicle were suspended and the remainder was left to the person in charge to do it manually. The last is a measure to prevent accidents. On the other hand, if the magnetic tape 10 is successfully found by the first or second step control, the vehicle is accelerated to a normal high speed of 24 m/min along the guiding path of the magnetic tape 10.

Next, FIG. 7 shows when the AGV deviates from the route due to overcoming obstacles on the route or when an unexpected external force is applied to the car, the control operation (departure prevention function) of the automatic guidance method of the present invention. In this case, the control device processes the action record of the magnetic sensor 7 at the moment of deviation, immediately determines the direction of deviation, turns the driving wheel 6 to the opposite direction of deviation, and searches the magnetic tape 10 at a low speed for a preset period of time (in this example, 8 seconds). This provides a high success rate for finding the tape 10, and since the detection of the tape 10 means that the vehicle is back on the guide path, the control can then accelerate the vehicle to resume its normal high speed operation. However, in this case, if the tape is not found within the preset time, the operation is immediately interrupted to prevent accidents, and the rest is left to the person in charge to operate manually.

Next, the vehicle constructed in this way shown in Figure 9, so that its four corners of the chassis 12 have universal casters 11 respectively, two driving wheels 6,6 are provided on both sides of the lower middle part of the chassis, and each driving wheel 6,6 is provided with a A drive device 5 is automatically controlled by a control device 8 which processes the signal detected by the magnetic sensor 7 . The vehicle shown in Figure 10 differs from that of Figure 9 only in that two universal castors 11 are provided, one at the front under the chassis and the other at the rear under the chassis. When the pair of drive wheels 6, 6 are synchronously controlled, the vehicle moves straight (forward and backward), and when the pair of wheels is differentially controlled, the vehicle makes a turning motion (also moves forward or backward). The automatic guidance method described above can be adopted in exactly the same way for both the car shown in Figure 9 and the car shown in Figure 10.

According to the automatic guiding method of the present invention, even if the magnetic sensor is not on the guiding path (tape) when starting the operation, the vehicle can automatically find the magnetic tape (guiding path) with a high probability and start running; Route, the vehicle can return to the guiding path with a high probability by automatically finding the tape (guiding path). The above reduces manual operation and obtains a more complete unmanned operation.

Claims (4)

1. the automatic guide method of a vehicle, this vehicle has a driving wheel, a magnetometric sensor, the magnetic that the guide path that is made of tape that the running route of this described vehicle in sensor detection upper edge, ground is placed produces, a drive unit and a pilot instrument by control device control, this control device is handled the signal that described sensor detects, and the method is characterized in that:

When (a) operation began, this vehicle was subjected to the described sensor of left-right rotation to search for the control of described guide path;

(b) if fail to find described guide path by above-mentioned control procedure (a), as second step, described vehicle is being subjected to turning to the control low-speed motion of some directions to search for described guide path fully described sensor, continue one section Preset Time, and,, then make described pilot instrument switched in opposite direction fully if do not find described guide path yet, continue low-speed motion, continue to double the Preset Time that once turns to before described;

(c) if found described guide path, then described vehicle to be subjected to accelerating to the control of normal speed to resume operation along described guide path by described control procedure (a) or (b); And

(d) if by described control procedure (a) or (b) in described Preset Time, do not find described guide path then to described vehicle shut-down operation.

2. the automatic guide method of a vehicle, this vehicle has a driving wheel, a magnetometric sensor, the magnetic that the guide path that is made of tape or analog that this described vehicle operating route in sensor detection upper edge, ground is placed produces, a drive unit, with a pilot instrument by control device control, this control device is handled the signal that described sensor detects, and the method is characterized in that:

(a) if described vehicle departs from route at run duration, then at first with described Vehicular shift to low speed, the decision offset direction, described pilot instrument turned to described depart from opposite direction, in one section Preset Time, carry out the search of described guide path, and when described vehicle was restored on the described guide path, described vehicle was accelerated to normal speed, to resume operation; And

(b) if described vehicle can not return on this guide path by described control procedure (a) in described Preset Time, then the operation of vehicle is terminated.

3. the automatic guide method of claim 1 or 2 described vehicles, this vehicle comprises a magnetic conductance type driving/driving unit, it is a drive unit and pilot instrument for this driving wheel outfit that a driving wheel is equipped with that this unit has, and one have the coaster that Qi Sijiao has the chassis of wheel, described drive unit is controlled from the control device of the signal of a sensor by a processing, this sensor is surveyed the magnetic of a guide path generation that is made of tape, described driving/driving unit attaching is in the lower surface on described chassis, and the feature of this method is as follows:

When the operation beginning, described pilot instrument is subjected to using the control of described driving wheel with described magnetometric sensor left-right rotation, to search for described guide path.

4. the automatic guide method of claim 1 or 2 described a kind of described vehicles, this vehicle comprises two driving wheels that central described lower surface both sides, described chassis are set, a magnetometric sensor that is arranged at front portion, described chassis, this sensor is surveyed the magnetic of the tape generation of the guide path placement in upper edge, ground, two drive units are that described driving wheel is respectively joined one, described drive unit is controlled automatically by control device, this control device is handled the signal that described magnetometric sensor detects, and pilot instrument, this pilot instrument drives described two driving wheels by the described drive unit of being controlled automatically by described control device differentially, the method is characterized in that:

When the operation beginning, described pilot instrument is controlled to come the described magnetometric sensor of left-right rotation by drive described two driving wheels differentially, to search for described guide path.

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