JPH04295906A - Travel controller for automatic traveling working car - Google Patents

Abstract

PURPOSE:To simplify the circuit structure and to reduce the cost by enabling the car to travel and stop without providing a new sensor nor a detecting circuit by deciding that the possibility that the vehicle leaves a guidance body reaches a set continuous frequency by a follow decision means. CONSTITUTION:An automatic traveling lawn mower is provided with an operation control unit 11 for which front and rear pickup coils 9 and 17 are connected and front-wheel and rear-wheel steering driving devices 12 and 19. The quantity of deviation of a sensor from a guidance cable 5 is judged from the difference of the electric signal outputted by the front pickup coil 9. An operation control signal which rotates a mobile member 8 in the direction wherein the quantity is reduced to '0' is outputted to the driving device 12. The quantity of deviation of a sensor 18 from the guidance cable 5 is judged from the difference of the electric signal outputted by the rear pickup coil 17. Then an operation control signal for reducing the quantity to '0' is outputted to the steering driving device 19.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel control device for an automatically traveling work vehicle that follows a guide provided within a work area.

0002

2. Description of the Related Art In the past, progress has been made in the development and practical use of self-driving work vehicles that are equipped with magnets, cables, and other derivatives through which alternating current is passed within a work area, and which travel along the derivatives.

[0003] Here, when the automatic traveling work vehicle deviates from the guided traveling course by the guide and becomes derailed, it is necessary to stop the automatic traveling work vehicle from traveling. For this reason, there are devices disclosed in Japanese Patent Application Laid-Open No. 61-272809 and Japanese Patent Application Laid-Open No. 1-287711 as devices for detecting that an automatic traveling work vehicle is in a derailed state.

0004

[Problem to be solved by the invention] JP-A-61-2728
In the devices for detecting a derailment state disclosed in Publication No. 09 and Japanese Patent Application Laid-open No. 1-287711, in addition to the sensor used to control steering along the guide, a new sensor for detecting a derailment state is used. A sensor is provided, making the circuit structure complicated.

[0005]

[Means for Solving the Problems] The present invention has a steering wheel connected to a steering drive device and a sensor for detecting a guide arranged in a work area, and detects the sensor based on detection data from the sensor. A memory for storing detection data from the sensor in an automatic driving work vehicle having a steering control means for determining an amount of deviation with respect to the guide and operating the steering drive device in a direction to make this amount of deviation "0". a comparison means for calculating a difference by comparing the stored previous detection data and the newly detected detection data; and determining the driving condition by comparing the difference calculated by the comparison means with a reference value. a following determination means for determining whether or not such determinations have been made consecutively for a set number of times or more when the traveling state determining means determines that there is a possibility that the vehicle has left the guide; A travel stop means is provided which determines that the automatic travel vehicle has separated from the guide body and stops the travel of the automatic travel work vehicle when it is determined that the automatic travel vehicle has continued for a predetermined number of times or more.

[0006]

[Operation] The previous detection data from the sensor is stored in the storage means, and the difference is detected by comparing the previous detection data stored in the storage means and the newly detected detection data by the comparison means. By comparing the difference with a reference value by the driving state determining means, it is determined whether or not there is a possibility that the automatically traveling work vehicle is traveling separated from the guide body. Then, the tracking determination means determines whether or not the possibility of detachment from the guide has continued for a set number of times or more, and if the possibility of detachment from the guide has continued for a set number of times or more, it is determined that the vehicle has detached from the guide and the traveling stop means causes the automatic traveling work vehicle to stop. Running is stopped.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained based on the drawings. On the abdomen of the self-driving lawn mower 1, which is a self-driving work vehicle,
A mower 4 is installed so as to be movable up and down between a front wheel 2, which is a steering wheel, and a rear wheel 3, which is a steering wheel. On the other hand, a guide cable 5, which is a derivative, is buried underground in the work area where the autonomous lawn mower 1 works, along the travel course on which the automatic lawn mower 1 travels. Both ends are connected to a signal transmitter 6.

A moving member 8 is attached to the front part of the automatic lawn mower 1 and extends in the front-rear direction and is rotatable in a horizontal plane around a support shaft 7. A front sensor 10, which is a sensor having a pair of left and right front pickup coils 9 for detecting a signal from the induction cable 5, is attached to the section.

Furthermore, the self-driving lawn mower 1 includes a control unit 11 which is a steering control means to which the front pickup coil 9 is connected, and a control unit 11 which is connected to the control unit 11 and is connected to the moving member 8. A front wheel steering drive device 12 is provided as a steering drive device. In the control unit 11, the amount of deviation between the sensor 10 and the induction cable 5 is determined based on the difference between the electrical signals output from the pair of front pickup coils 9, and further, the amount of deviation determined is determined. “
A steering control signal for rotating the moving member 8 in the direction of 0'' is calculated, and this steering control signal is output to the front wheel steering drive device 12.

[0010] Here, the front wheel 2 is connected to a front wheel link mechanism 13.
The front wheel link mechanism 13 is connected to the moving member 8 so as to steer the front wheels 2 as the moving member 8 rotates. Further, a front wheel steering angle sensor 14 for detecting the steering angle of the front wheels 2 is provided on the outer circumference of the support shaft 7.

On the other hand, also on the rear wheel 3 side, the front wheel 2
Similarly to the side, a movable member 16 that extends in the front-rear direction and is rotatable in a horizontal plane around a support shaft 15, and a movable member 1
6 and is attached to the tip side of the induction cable 5.
A rear sensor 18, which is a sensor having a pair of left and right rear pickup coils 17 for detecting signals from the vehicle, and a rear wheel steering drive device 19, which is a steering drive device connected to the moving member 16, are provided. The rear pickup coil 17 and the rear wheel steering drive device 19 are connected to the control unit 11. In the control unit 11, the amount of deviation between the sensor 18 and the induction cable 5 is determined based on the difference between the electrical signals output from the pair of rear pickup coils 17, and further, the amount of deviation determined is determined as " A steering control signal for rotating the moving member 8 in the direction of 0'' is calculated, and this steering control signal is output to the rear wheel steering drive device 19.

[0012] Here, the rear wheel 3 is connected to a rear wheel link mechanism 20.
The rear wheel link mechanism 20 is connected to the movable member 16 so as to steer the rear wheels 3 as the movable member 16 rotates. Further, a rear wheel steering angle sensor 21 is provided on the outer circumference of the support shaft 15 to detect the steering angle of the rear wheel 3.

Next, the control unit 11 includes storage means for storing detection data from the sensors 10, 14, 18, and 21, and storage means for storing detection data from the sensors 10, 14, 18, and 21, and storage means for storing detection data from the previous data stored in the storage means and newly detected detection data. a comparison means for comparing data and calculating the difference; a driving state determining means for determining the driving state of the self-driving lawn mower 1 by comparing the difference calculated by the comparing means with a reference value; and a driving state determining means. If the means determines that there is a possibility that the user has deviated from the running course along the guide cable 5, the follow-up determining means determines whether or not the determination has been made consecutively for a set number of times or more; If it is determined that the automatic traveling lawnmower 1 continues, it is determined that the automatic traveling lawn mower 1 has left the traveling course along the guide cable 5, and automatically stops the traveling of the automatic lawn mower 1.

[0014] In such a configuration, first, the state in which the self-driving lawnmower 1 is detached from the guide cable 5 is that both the front wheel side and the rear wheel side are detached, and the case where the front wheel side and the rear wheel side are detached. There are cases in which one of the parties has left the party. Note that when the front wheel side (or rear wheel side) is disconnected from the induction cable 5, the electric signals from the pickup coil 9 (or 17) are both "0", so the sensor 10 (or 18) The detection data of becomes “0”. Furthermore, the detection data from the sensor 10 (or 18) is “
0", the steering control signal output from the control unit 11 also becomes "0", and the steering angle sensor 14
The detection data from (or 21) also becomes "0". however,
The detection data from the sensors 10, 14, 18, and 21 may not be "0" due to the influence of noise.

Next, a description will be given of a running state determining means for determining whether or not there is a possibility that the automatically traveling lawn mower 1 has separated from the guide body 5. There are three conditional expressions for judgment by this running judgment means, and the conditional expression (
1) is (FJ<α)∩(RJ<α)∩(FS<β
)∩(RS<β), conditional expression (2) is (FJ<α)
∩(FS<β), conditional expression (3) is (FR<α)∩
(FR<β). However, FJ: the difference between the previous detection data of the front sensor 10 and the newly input current detection data, RJ: the difference between the previous detection data of the rear sensor 18 and the newly input current detection data , FS: difference between the previous detection data of the front wheel steering angle sensor 14 and the newly input current detection data, RS
: Difference between the previous detection data of the rear wheel steering angle sensor 21 and the newly input current detection data, α: Amount of change due to the influence of noise in the detection data of the sensors 10 and 18, β: The difference of the detection data of the sensors 14 and 21 This is the amount of change in detected data due to the influence of noise. If conditional expression (1) is satisfied, it is determined that there is a possibility that both the front wheel side and the rear wheel side have separated from the guidance cable 5, and if conditional expression (2) is satisfied, the front wheel side is determined to be disconnected from the guidance cable 5. It is determined that there is a possibility that the rear wheel has separated from the guide cable 5, and if conditional expression (3) is satisfied, it is determined that there is a possibility that the rear wheel side has separated from the guide cable 5.

Next, a follow-up determining means for determining whether or not the automatically traveling lawn mower 1 has separated from the guide cable 5 will be explained. If any of conditional expressions (1), (2), or (3) is satisfied, there is a possibility that the self-driving lawn mower 1 has separated from the guidance cable 5, but at the same time, the amount of deviation with respect to the guidance cable 5 It is conceivable that the vehicle is running in a state where the front wheels 2 and the rear wheels 3 are not steered because the guide cable 5 is substantially straight or arcuate with a constant radius while the vehicle is traveling in a state where the distance is "0". However, since the probability of such a running state continuing for a long time is extremely small, conditional expressions (1), (2), (
It is determined whether the state satisfying 3) has continued for a set number of times or more, and conditional expression (4) of A<t or conditional expression (5) of B<t is determined.
), it is determined that the automatic mower 1 has separated from the guidance cable 5. However, A, B: arbitrary set number of times, t: consecutive number of states satisfying conditional expressions (1), (2), and (3).

[0017] Now, a description will be given of the travel control in which the automatic mower 1 is caused to travel following the guide cable 5 and automatically stop traveling when the lawn mower 1 is separated from the guide cable 5, based on the flowchart shown in FIG. .

First, in step 1, the front sensor 1
0, rear sensor 18 and front wheel steering angle sensor 14
Detection data from the rear wheel steering angle sensor 21 is input to the control unit 11, and further, "FJ", "RJ", "FS", and "RS" are calculated by the comparison means.

Next, in step 2, the running state determining means determines that (FJ<α)∩(RJ<α)∩(FS<
It is determined whether conditional expression (1) of β)∩(RS<β) is satisfied. If conditional expression (1) is satisfied, it is determined that there is a possibility that both the front wheel side and the rear wheel side of the self-driving lawn mower 1 have separated from the guide cable 5.

If conditional expression (1) is satisfied, the tracking determining means determines in step 3 whether the state satisfying conditional expression (1) has continued for a set number of times "A" or more.

[0021] If the consecutive number of times does not reach "A", as shown in step 4, the sensors 10 and 14
, 18, and 21 are stored in the storage means as the previous detection data, and the number of determinations t is incremented by one.

On the other hand, if conditional expression (4) is satisfied in step 3, it is determined that both the front wheel side and the rear wheel side are disconnected from the guide cable 5, and as shown in step 5, An engine error flag is set and the running of the automatically running lawn mower 1 is stopped by the running stop means.

If conditional expression (1) is not satisfied in step 2, then in step 6, the driving state determining means determines whether conditional expression (2) of (FJ<α)∩(FS<β) is satisfied. It will be judged. If conditional expression (2) is satisfied, it is determined that there is a possibility that the front wheel side of the self-driving lawn mower 1 has separated from the guide cable 5.

If conditional expression (2) is satisfied, the follow-up determining means determines in step 7 whether the state satisfying conditional expression (2) has continued for a set number of times "B" or more.

[0025] If the consecutive number of times does not reach "B", as shown in step 8, the sensors 10, 14
, 18, and 21 are stored in the storage means as the previous detection data, and the number of determinations t is incremented by one.

On the other hand, if conditional expression (5) is satisfied in step 7, it is determined that the front wheel side is detached from the guide cable 5, and as shown in step 5,
An engine error flag is set and the running of the automatically running lawn mower 1 is stopped by the running stop means.

If conditional expression (2) is not satisfied in step 6, then in step 9, the driving state determining means determines whether conditional expression (3) of (FR<α)∩(FR<β) is satisfied. It will be judged.

If conditional expression (3) is satisfied, the follow-up determining means determines in step 7 whether or not the state satisfying conditional expression (3) has continued for a set number of times "B" or more;
Based on this determination result, the running is stopped in step 5, or the detected data is stored in step 8, and the number of determinations t is increased by +1.

On the other hand, if conditional expression (3) is not satisfied in step 9, as shown in step 10,
The detection data from the sensors 10, 14, 18, and 21 are stored in the storage means as the previous detection data, and the number of determinations t is set to zero.

[0030]

Effects of the Invention As described above, the present invention provides a storage means for storing the previous detection data from the sensor, and compares the detection data stored in the storage means with the newly detected current data to determine the difference. a comparison means for calculating the difference calculated by the comparison means with a reference value to determine the driving condition; and a determination by the driving condition determination means that there is a possibility that the vehicle has separated from the derivative. If the determination is repeated for a set number of times or more, the following determination means determines whether the determination continues for a set number of times or more, and if the following determination means determines that the determination continues for a set number of times or more, it is determined that the guide has separated from the guide. By providing a travel stop means for stopping the movement of the automated driving work vehicle, the automatic driving work vehicle can detect when the automated driving work vehicle has separated from the guide body. This can be done without providing a new sensor or detection circuit for this purpose, and therefore has the advantage of simplifying the circuit structure and reducing costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a travel control system.

FIG. 2 is a side view showing the entire self-driving lawn mower.

FIG. 3 is a flowchart showing a travel control state.

[Explanation of symbols]

1 Automated driving work vehicle 2, 3 Steering wheel 5 Derivatives 10,18 Sensor 11 Steering control means 12, 19 Steering drive device

Claims (1)

[Claims] 1. A steering wheel connected to a steering drive device and a sensor for detecting a guide body disposed within a work area, and based on detection data from the sensor, the sensor and the guide body are connected to each other based on detection data from the sensor. In an automatic driving work vehicle having a steering control means for determining an amount of bias and operating the steering drive device in a direction to set the amount of bias to "0", a storage means for storing detection data from the sensor; a comparison means for calculating a difference by comparing the previously detected detection data and newly detected detection data; and a driving condition determination device for determining the driving condition by comparing the difference calculated by the comparison means with a reference value. means, follow-up determining means for determining whether or not the determination has continued for a set number of times or more when the traveling state determining means determines that there is a possibility that the vehicle has left the guide; A travel control device for an automatic traveling work vehicle, characterized in that a travel stop means is provided for determining that the automatic traveling work vehicle has separated from the guide body and stopping the travel of the automatic travel work vehicle when it is determined that the vehicle continues.