JPS5922106A - Automatic running vehicle - Google Patents

Abstract

PURPOSE:To perform excellent follow-up run control without causing hunting by providing two groups of sensors which detect shifts from a specific line in a front and rear direction of a vehicle body. CONSTITUTION:Two groups of sensors A and B for detecting shifts from the specific line L are provided in the front and rear direction of the vehicle body 1. When those sensors A and B detect shifts from the specific line L in the same direction, it is judged that the body 1 deviates substantially in parallel or in a state close to it. When the shifts detected by the sensors are different in direction, it is judged that the body deviates slantingly. Then, appropriate steering control is performed according to the decision made above to perform the speedy, excellent follow-up control.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for detecting a deviation from a predetermined line defined by a boundary MVC between an unmowed area and a mowed area using a sensor, such as in an autonomous lawn mowing vehicle. The present invention relates to an automatic driving vehicle configured to perform automatic steering control so as to follow a vehicle.

Conventionally, this kind of self! The 41J running hL@ was configured as follows. That is, a set of sensors are installed at the front of the vehicle body to detect deviations from a predetermined line to be followed, and when the sensors detect deviations from the predetermined line, the deviation is corrected. Steering wheels (through K
The vehicle was configured to control the steering of the vehicle (i.e., wheels).

With such a conventional configuration, it is possible to detect that the vehicle body has simply deviated from a predetermined line, and it is possible to detect whether the vehicle body has deviated from the predetermined line so that it is parallel to the predetermined line. Not only is it impossible to determine whether the vehicle has deviated so that it has an angle with respect to the vehicle body, but it is also impossible to determine whether the vehicle body has deviated in any way, by controlling the steering LFT wheels to change the direction of the vehicle body. Since the control is performed using the same pattern of correction, the vehicle body travel trajectory becomes a zigzag pattern with a relatively short period, which has the disadvantage that it is easy to fall into a so-called hunting state.

The present invention has been made in view of the above-mentioned conventional situation, and its purpose is to be able to determine whether the deviation of the vehicle body from a predetermined line is of the type described above, and to make it possible to determine whether the deviation of the vehicle body from a predetermined line is An object of the present invention is to provide an automatic driving vehicle that can perform appropriate steering control depending on its type.

In order to achieve the above object, an automatic driving vehicle according to the present invention includes:
An automatic driving vehicle configured to autonomously control steering so as to follow a predetermined line, and equipped with two sets of sensors arranged in the rear direction of the vehicle nr1 for detecting the displacement from the predetermined line described in 1f■. In addition, all of the if+ wheels and the rear wheels are configured to have a steering drive function, and both of the two sets of sensors are configured to move from the prescribed line in III to the same side.
If mtr is detected, both the front wheels and the rear wheels are fully driven to perform steering control; If only one of the two sets of sensors detects a deviation from the predetermined line, the O
A feature of the present invention is that a control device is provided which is configured to drive only one of the f1 wheel paralytic rear wheels to perform steering control.

Due to this percentage structure, the following excellent effects have been achieved.

In other words, even though the configuration is extremely simple, with only two sets of sensors installed in the longitudinal direction of the vehicle body to detect deviations from a predetermined line, if both of the two sets of sensors detect deviations from the predetermined line to the same side. In this case, it is determined that the vehicle body is deviated substantially parallel to or close to a predetermined line, and two sets of sensors each detect deviations from the predetermined line to different sides. , and if only one sensor detects a deviation from the predetermined line, it is determined that the vehicle body is tilted and deviates from the predetermined line. In addition, if the vehicle body deviates from being substantially parallel to a predetermined line, it can now be reliably identified by steering control of both the front and rear wheels. The vehicle body is quickly moved along a predetermined line by moving the vehicle in parallel, but if the vehicle body deviates from tilting relative to the predetermined line, the vehicle body is first moved by controlling the steering of only one of the front wheels or rear wheels. By configuring the structure so that appropriate steering control can be performed depending on the state of the vehicle, such as correcting the direction of the When the car body returns to the state along the predetermined line as a result of correction, the direction of the car body can also be made to be almost in the direction of the predetermined line, so there is no hunting condition as in the conventional case, and the direction of the car body returns to the state along the predetermined line. This made it possible to perform extremely good tracking on the traveling side.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Fig. 1, the lfT rear wheel (2) of the vehicle body ill
.

The lawn mowing device (4) is suspended in the middle part of (3) so as to be movable downward L, and a line is provided to determine the boundary (L) between the unmowed area and the mowed area of the lawn, which serves as a predetermined running line. As detection sensors, two sets of copying sensors fAl and fnl are provided on the left and right sides of the front of the vehicle body (1), respectively, to configure a lawn mowing vehicle as an autonomous vehicle.

Then, the melodic wheels +21, +2] and the rear wheels (
3).

(3) is mounted on each steering wheel, and the copying sensor (4) is mounted on each steering wheel.
), (B), based on the detection result of the boundary (L), the hydraulic cylinders (5A) and (5B) are designed to be steered by a predetermined amount in the left and right direction. The front and rear wheels 12) and +3+ are both configured to function as driving wheels, and are configured to allow the vehicle body (1) to travel the entire distance by transmitting power from the engine (E) (the mechanism is not shown). 9) Optical sensors constituting the copying sensors (4) and (B)
(Sl + 82), (S3, 34) are U-shaped sensor frames +61, as shown in FIG.
A sensor mounting frame (7) provided on the lawn mowing device (4) is arranged so as to form a substantially rectangular shape in plan view at a predetermined interval in the left and right direction and also at a predetermined interval in the rear direction. A light-emitting element (Pl) and a light-receiving element (P2) are provided as a pair on the inner facing surfaces of the sensor frames 161 and +6+, respectively, and between the light-emitting element (Pl) and the light-receiving element (P2). In addition, the grass surface that is introduced as the main body FI+ runs
By sensing nothingness, the boundary between uncut land and cut land (L
).

In addition, the sensors (Al, tel) are optical seven-line (S,), (S,), (S3), (
The sensor may be constructed using any type of sensor, including contact type and non-contact type.

Hereinafter, the copying sensor history J with the above configuration, (I(+
A control system that controls the steering of the vehicle body ill based on information from the vehicle will be described.

As shown in FIG. 3, the control system e has a microcomputer as its main part. A signal from the Fjfl imitation sensor (B) is input to the control device (8) by removing the human interface (9), and based on this signal, the electromagnetic valves (IOA) and (JOB) are operated. Then, the hydraulic cylinder (5A) which is the actuator,
(5B) to output a control signal which is the calculation result to the output interface (11) in order to control the steering of the front wheels +2+, +21 and the rear wheels +31, +31.

Next, the operation of the control device (8) will be explained based on the flowchart shown in FIG. 4 and the table shown in FIG. 5.

Basically, before the start of driving, this program first manually determines which side of the vehicle body, the tracing sensor on the left side of the vehicle body or the right side of the vehicle body, to perform tracing traveling control using a selection switch (not shown), etc. After that, tm two sets of scanning sensors +A+, (4 forming Bl)
The detection signals from all of the three optical sensors (Sl) to (S4) are detected by Kokichi, who refers to a pre-stored table as shown in FIG.
Only the steering link Luca l1fli wheels 12+,+
21 O, J: H Rear wheels 131, 13N7) A 3-state 5tate signal that determines whether to steer both or straight ahead control, a Flagl signal that indicates the steering direction, and a steering amount. The flag2 signal is converted into three types of control signals, and based on these eight control signals, the electromagnetic valve (IO
A), (IOB) are driven so that the wheels are steered in a predetermined direction and by a predetermined amount, and the running direction is automatically changed so that the vehicle body automatically runs in a predetermined direction along the boundary (L). This is configured to be modified.

That is, in the table above, 5tate l indicates neutral, and electromagnetic pulp (IOA), (IOB)
Control to put the vehicle in neutral state and move the vehicle body +11 straight, 5t
ate 2 controls moving the car body +11 in parallel by driving both the electromagnetic valves (IOA) and (IOB) and steering both lfl wheels +21 and +31, and 5tate 3 drives only the electromagnetic valve (IOA). This corresponds to control for changing the direction of the vehicle body by fully steering only 1q wheel +21 and +21.

Further, F J, a g 1 indicates the steering direction, and 0'' indicates steering toward mowed land, and +1'' indicates steering toward unmowed land, respectively.

Furthermore, Flag2 is set to +0” to lower the steering acid, +
1”, the electromagnetic valve (I
This shows that the duty ratio of pulse No. 18, which is a valve drive signal output from the output interface (river), is changed in order to drive OA) and (IOB).

In this embodiment (C), the configuration is such that only the front wheels (2+, +21) are steered to correct the running direction when the vehicle body (1) is inclined with respect to the boundary (L) shown in Bstate 8. Although this has been adopted, a configuration may also be adopted in which the running direction is corrected by steering only the rear wheels +31 and +31 or both of the m+1 rear wheels in opposite directions.

Further, a copying sensor (A) detects the boundary (L).

(I and b show a configuration in which B1 is placed 1X in the n++ rear direction of the vehicle body (1).
They may be arranged at the rear respectively.

Furthermore, my father installed two sets of copying sensors (A) on the left and right sides of the vehicle f11.
,, B) , (A, B) Which side of the car body is the uncut land on which side of the car are the kumquats? Of course, this depends on whether the left and right sensors (A,
B) The switching between the selections of (A and B) can be done automatically by separately installing a sensor or the like to detect the position of the uncut land, instead of the manual configuration adopted in this embodiment. Good too.

Next, another embodiment of the present invention will be described based on FIG.

Figure 6 shows the guideline of the driving course defined by buried tracks, color lines, etc. It is a drawing showing the relationship between (I-) and the sensor arrangement for detecting it.

That is, two sets of line detection sensors (A') and (B') arranged in the front-rear direction are connected to three sets of optical sensors (s'l + s'2+) arranged adjacently in the left-right direction, respectively.
S'3) + ('', S's + S'6), and the center sensor (S'
2) Steering control is performed so that the state in which , (s',) detects the line (L) corresponds to the state in which the vehicle follows the specific line (Ll).

1f (Era Senner (S', ) to (S'6) is basically the same structure as the optical sensor (S- to (B4)) shown in Figure 2 of Chapter 10, but its light emitting element ( Pl) and photoreceptor (
The arrangement of P2) was changed from being on opposing surfaces to facing downward on the same surface, and configured to detect the presence or absence of this line (L) by detecting the reflected light from the line (L). It is.

The case where only the central optical sensors (St) and (St) detect the line (L) is the 5tate of the above embodiment.
1, and the optical sensors at both ends (s'1), (s'4)
Or optical sensor (SS), (B4) is line (L)
'f, the case where the detection is the same (corresponds to 5tate 2, and the case where the other line detection sensors (A') and (B') detect deviations in the opposite direction corresponds to 5tate 8, respectively, in the above embodiment) The direction of travel is automatically corrected in the same way.

In addition, FIG. 7 shows these optical sensors (S'l) to (s'6).
This is a table of control parameters corresponding to combinations of line (L) detection results, and the same symbols used in the table shown in FIG. 5 indicate the same contents.

Further, although the line detection sensors (A') and (B') are each constructed of eight optical sensors, a large number of sensors may be provided to expand the line detection range.

[Brief explanation of the drawing]

The drawings show an embodiment of an automatic driving vehicle according to the present invention, and the first embodiment
The figure is an overall plan view of the lawn mowing stop, Figure 2 is a front view of the main parts of the copying sensor, Figure 8 is a block diagram of the control system, and Figure 4 is a block diagram of the control system.
5 is a flowchart showing the operation of the control device, FIG. 5 is a discrimination table for sensor detection signals, FIG. 6 is a conceptual diagram of line detection in another embodiment, and FIG. 7 is a discrimination table for sensor detection signals. tel, tel...till wheel, [31
, t3)...Rear front wheel, (8)...Control device, (L)...Predetermined line, (A), tn
l...Line detection sensor-0

Claims (1)

[Claims] ■ An automatic driving vehicle configured to automatically control steering so as to follow a predetermined line (L),
Two sets of sensors Ul and (B) for detecting deviation from the predetermined line (L) are arranged in parallel in the longitudinal direction of the vehicle body, and front wheels +2), +2) and rear wheels 13]
.
) to the same side, the above 11f
T wheels +21, [21 and rear wheels +31, +
31 to perform steering control, the two sets of sensors (A+, (Bl) are connected to the predetermined line (■7), respectively.
) to different sides, and 1
(f) When only one of the two sets of sensors (B) detects a deviation from Lj, the front wheel f21, +21 and the rear wheel +3,
1. An automatic driving vehicle, characterized in that it is provided with a control device (8) configured to perform steering control by driving only one of the +31. ■ When the two sets of sensors (B) respectively detect movement from the nfI predetermined line (L) to different sides, the front wheels (21, +2+ and the rear wheels 131, 131,
131, and if only one of the two sets of sensors +A+, (Bl detects the displacement from the predetermined line (Lj), then the front wheels !21, +21 The self-help system according to claim 0, wherein the control device (8) is configured to reduce the amount of steering of the - of the rear wheels +3+ and +3+. Strike direction of the car.