JPH05216536A - Steering controller for unmanned running vehicle - Google Patents

Abstract

PURPOSE:To provide a satisfactory steering precision even in the case of the increase of the vehicle velocity or the heavy vehicle weight with respect to the unmanned running vehicle which detects the deviation from a running course and is run by automatic driving while obtaining a steering speed indication value based on the extent of this deviation. CONSTITUTION:A means which detects an extent (alpha) of deviation from the running course, a deviation speed calculating means 68 which obtains a change speed (beta) of the extent of deviation, a deviation acceleration calculating means 70 which calculates a change acceleration (gamma) of the extent of deviation, and an indication value calculating part 80 which uses the speed beta and/or the acceleration (gamma) and the extent (alpha) of deviation to obtain a steering speed indication value (w) are provided. The indication value calculating part 80 uses at least the extent (alpha) of deviation and the acceleration (gamma) at the time of the increase of the extent (alpha) of deviation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unmanned vehicle capable of guiding while detecting a guide wire laid on a road surface.

[0002]

2. Description of the Related Art In a golf car, an unmanned vehicle in a factory, or the like, a vehicle capable of unmanned guidance, that is, an unmanned traveling vehicle, is detected by a sensor such as an induction coil provided on the vehicle body side, which detects a guide wire buried along a traveling course. It is known. For example, a coil (induction coil) that detects an AC magnetic field formed by this AC current is installed on the vehicle side while an AC current is being supplied to the induction line, and a change from the detection output of this coil causes a deviation from the guide wire of the vehicle. That is, there is one that detects the deviation amount and steers the steered wheels of the vehicle so that the deviation amount falls within a predetermined range.

In this type of vehicle, the input voltage of the steering servomotor, that is, the steering instruction angle, the actual steering angle θ _0, and the deviation amount y ₁
And a control method that reflects the change rate y ₂ of the deviation amount have been conventionally known (for example, Japanese Patent Publication No. 55-31).
927). That is, the steering instruction angle θ is obtained by θ = aθ ₀ + by ₁ + cy ₂ . Here, a, b, and c are constants corresponding to the feedback gain.

According to this method, since the change rate y _{2 of the} deviation amount is reflected, even if the deviation amount y ₁ is small, for example, when the change rate y ₂ or the actual steering angle θ ₀ becomes large, the steering instruction angle θ changes. Also grows. Therefore, the steering accuracy is improved.

[0005]

However, when the vehicle speed increases or the weight of the vehicle body increases, the inertial force also increases. Therefore, it is difficult to sufficiently increase the accuracy by such a control method.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a steering control device for an unmanned vehicle capable of improving the steering accuracy even when the vehicle speed increases or the vehicle weight is large. The purpose is to provide.

[0007]

According to the present invention, an object of the present invention is to detect a deviation from a traveling course, and to obtain a steering speed instruction value based on the deviation amount, and in an unmanned traveling vehicle which travels by automatic piloting, the deviation from the traveling course Means for detecting a deviation amount (α), deviation speed calculating means for obtaining a changing speed (β) of the deviation amount, deviation acceleration calculating means for obtaining a changing acceleration (γ) of the deviation amount, the speed β and the acceleration An instruction value calculation unit that obtains a steering speed instruction value (w) using at least one of (γ) and the deviation amount (α) is provided, and the instruction value calculation unit decreases when the deviation amount (α) increases. Both are achieved by a steering control device for an unmanned vehicle, which uses the deviation amount (α) and the acceleration (γ).

[0008]

1 is a conceptual diagram of an engine-driven golf car according to an embodiment of the present invention, FIG. 2 is a block diagram of its steering control system, and FIG. 3 is its operation flow chart. This golf car is capable of switching between an unmanned traveling mode in which an unmanned vehicle is guided and a manual traveling mode in which a driver rides and manually steers.

In these drawings, reference numeral 10 denotes a vehicle body of a golf car as an unmanned vehicle according to the present invention. Front wheels 12, 12 as steering wheels are arranged at the front part of the vehicle body 10, and rear wheels 14, 14 as driving wheels are arranged at the rear part. Further, at the rearmost portion of the vehicle body 10, there is provided a step 16 for the operator to get in during manual operation.

Reference numeral 18 is a carrier for loading luggage fixed to the front part of the vehicle body 10. A golf bag is placed on the carrier 18.

At the center of the vehicle body 10 in the width direction, a steering shaft 20 extends obliquely forward and upward toward the rear of the vehicle body.
Is rotatably held. This steering shaft 20
A steering handle 22 is attached to the upper end of the. An accelerator lever 24 is attached to the right end of the handle 22, and a brake lever 26 is attached to the left end.
These are used in a manual driving mode in which a person rides and steers manually.

A steering arm 28 is fixed to the lower end of the steering shaft 20. The turning end of the steering arm 28 is connected to the knuckle arms 32, 32 of the left and right front wheels 12 via steering rods 30, 30.

Reference numeral 36 is an electric motor for automatic operation which operates in the unmanned traveling mode, and is fixed to the vehicle body 10 side.
The rotation of the motor 36 is transmitted to the steering shaft 20 by the toothed belt 38. A gear may be used instead of the belt 38. A pair of left and right guide wire sensors 40 are arranged below the carrier 18, and detect a guide wire 42 laid on the road surface along the traveling route. Each sensor 40, 40
Output changes depending on the distance from the guide wire 42, the control device 48 to be described later determines the deviation of the vehicle body 10 from the guide wire 42, that is, the deviation amount α, based on the difference between the outputs of the sensors 40, 40. You can

The sensors 40, 40 may be swung right and left within a predetermined angle range in synchronization with the turning of the steering shaft 20. In this case, the deviation amount α is obtained by predicting the direction change of the vehicle body 10 due to the steering of the front wheels 12, and the steering accuracy by unmanned guidance can be improved. The outputs of the sensors 40, 40 also change depending on the road surface and the inclination of the vehicle body 10 in the left-right direction. Therefore, in order to prevent the decrease in accuracy due to this output change, the deviation amount α may be obtained by arranging the three sensors 40 at equal intervals and comparing the outputs of the three sensors 40.

The golf car 10 can be selected from an unmanned automatic mode and a manual mode in which the steering wheel 22 is operated. In the automatic mode, the motor 36 is controlled by the steering controller 44 (FIGS. 1 and 2). That is, based on a command from the main controller 46, the steering controller 44 rotates the motor 36 rightward or leftward by a predetermined rotation amount. The steering control device 48 includes the steering controller 44 and the main controller 4
6 and so on.

Next, the power system will be described. Reference numeral 50 is an engine mounted near the center of the vehicle body 10, and 52 is a rear wheel 1.
It is a drive case disposed between Nos. 4 and 14. The crankshaft rotation of the engine 50 is transmitted to the input shaft of the drive case 52 via the V-belt type automatic transmission 54. An electromagnetic brake (not shown) is interposed between the transmission 54 and the input shaft of the transmission case 52. This electromagnetic brake is a spring-closed type that is excited when the vehicle is running to release the brake and is de-excited when the main power is turned off to apply the brake.

The drive case 52 includes an input shaft and the rear wheel 1.
A disc brake for restricting rotation of a shaft (not shown) interlocking with the axle of No. 4 is attached. This brake is manually operated by the brake lever 26 of the handle 22. Therefore, the output of the engine 50 is transmitted to the input shaft of the drive case 52 via the transmission 54, and is transmitted to the rear wheel 14 via the reduction gear and the differential device (both not shown) in the drive case 52. .. A mechanical governor is attached to the engine 50 to control the throttle valve opening of the carburetor so as to limit the traveling speed in the manual mode.

A throttle valve (not shown) of a carburetor connected to the engine 50 is opened and closed by either the accelerator lever 22 or a step motor (not shown) via a switching device. That is, in the manual mode, the switching device disengages the electromagnetic clutch and transmits the rotation of the accelerator lever 22 to the throttle valve. On the other hand, in the automatic mode, the switching device 96 engages the electromagnetic clutch to open and close the throttle valve by the rotation of the step motor. The throttle valve opening at this time is detected by the throttle sensor and fed back to the main controller 46, and this opening is controlled to be the target opening.

Next, a steering control device that operates in the unmanned traveling mode will be described. The outputs of the guide wire sensors 40, 40 are input to the main controller 46 via the amplifiers 60, 60. The main controller 46 has a microcomputer (CPU) 62, and the outputs of these amplifiers 60, 60 are digitized by an input interface (IF) 64 and input to this CPU 62.

The CPU 62 calculates the deviation of the vehicle body 10 from the guide wire 42, that is, the deviation amount α, based on the outputs of the sensors 40, 40. This arithmetic function is shown as an α arithmetic unit 66 in FIG. The CPU 62 also causes the β calculator 68 to calculate a change speed β, which is a change with time of the obtained deviation amount α. Further, the CPU 62 calculates the acceleration γ which is a change with time of the speed β by the γ calculation unit 70.

On the other hand, the vehicle speed V is input to the CPU 62. For example, a vehicle speed sensor 72 that outputs a pulse in synchronization with the rotation of the rear wheels 14 is attached to the drive case 52, and the output of this sensor 72 is C through an interface (IF) 74.
Input to PU62. The CPU 62 calculates the vehicle speed V by counting the output pulses of the sensor 72 in the vehicle speed calculation unit 76.

The CPU 62 controls the deviation amount α, the deviation speed β,
The steering speed instruction value w is calculated by the following equation using the deviation acceleration γ. w = k ₁ α + k ₂ β + k ₃ γ where k ₁ , k ₂ , and k ₃ are constants determined by the operating conditions such as the vehicle speed V. These constants k ₁ , k ₂ and k ₃ are C
It is previously input to the memory 78 incorporated in the PU 62 or an external memory. The CPU 62 reads the constants k ₁ , k ₂ and k ₃ according to the operating conditions from the memory 78 and repeats the calculation of the instruction value w. In FIG. 2, reference numeral 80 is an instruction value calculation unit that performs this calculation.

The steering speed instruction value w thus obtained is input to the steering controller 44 through the interface 82, and the motor 36 is steered at the steering speed corresponding to the instruction value w.

Next, an operation example of this embodiment will be described with reference to FIG. First, in the automatic running mode after the power is turned on, a departure signal is input by a remote control such as a manual start switch or a remote controller provided on the vehicle. Then, the vehicle body 10 starts to start the operation shown in FIG. 3 (step 10
0). The CPU 62 first calculates the deviation amount α based on the output of the sensor 40 (step 102). Further, the deviation velocity β and the deviation acceleration γ are calculated (step 104).
The calculation results α, β and γ are stored in the CPU 62 or an external memory (not shown).

Next, the CPU 62 obtains the vehicle speed V by counting the output pulses of the vehicle speed sensor 72. CPU
Reference numeral 62 determines the operating condition based on the vehicle speed at this time and the deviation amount α, the speed β, the acceleration γ, etc., and reads out the constants k ₁ , k ₂ and k ₃ suitable for the operating condition from the memory 78. Then, the steering speed instruction value w is calculated by the calculation unit 80.

There are various methods for determining the driving conditions. In the embodiment shown in FIG. 3, the constant k is determined based on the vehicle speed V.
Change ₁ , k ₂ , and k ₃ . That is, the vehicle speed V is 3 km / h
If the following (step 108), as constants k ₁₁ , k ₂₁ ,
k ₃₁ is read (step 110). If 3 <V <6km / h (step 112), reads the _{k 12, k 22, k 32} ( step 114). If V ≧ 6 km / h (step 116), k
₁₃ , k ₂₃ and k ₃₃ are read (step 118).

Then, the instruction value w is calculated using the read constants k ₁ , k ₂ , k ₃ and the deviation amount α, velocity β, and acceleration γ (step 120). Based on the instruction value w output by the CPU 62, the motor 36 is controlled to reach the steering speed (step 122). The above operation is basically repeated while the vehicle body 10 is running (step 12
4).

In this embodiment, when the stop signal is input by remote control such as a manual stop switch or a remote controller (step 126), measurement of time t is started (step 128), and this time t becomes the set value T. When it reaches (step 130), the instruction value w is set to 0 (step 132).
Until the time t reaches T, the process returns to step 102 and the steering control system continues to operate. This means that the vehicle speed V is set to 0 when the vehicle is stopped by remote control such as a manual stop switch or remote control.
This is because if the deviation remains, the steering control system will continue to operate, and steering vibration may occur.

According to the vehicle speed V, the constant k ₁ ,
Although k ₂ and k ₃ are determined, the constant may be determined according to other running conditions. For example, when the deviation amount α increases while accelerating, k ₁ , k ₂ , and k ₃ are all positive constants, and the deviation amount α increases while decelerating, decreases while decelerating, or decreases while accelerating. In that case, any of the constants, for example, k ₂ and k ₃ may be set to 0 or negative.

When the deviation amount α increases (the speed β is positive), the deviation amount α is at least irrespective of whether the acceleration γ is positive or negative.
And acceleration γ are used to obtain w = k ₁ α + k ₃ γ. In this case, since the acceleration γ has a function of predicting the deviation in the direction of decreasing the deviation, it is suitable for improving the steering accuracy.

When the deviation decreases, it is desirable to obtain the instruction value w from the deviation amount α and the speed β regardless of whether the acceleration γ is positive or negative. This is because at this time, the term k ₂ β due to the speed β acts as a brake on the term k ₁ α due to the deviation amount α.

[0032]

As described above, according to the present invention, when the deviation amount (α) is increasing, the steering speed instruction value w is calculated using at least the deviation amount (α) and the acceleration (γ). The effect of improving accuracy is obtained.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an engine-driven golf car that is an embodiment of the present invention.

FIG. 2 is a block diagram of the steering control system.

[Fig. 3] Flow chart of the operation

[Explanation of symbols]

 12 front wheels 36 steering motor 44 steering controller 46 main controller 48 steering control device 66 deviation amount calculation unit 68 deviation speed calculation unit 70 deviation acceleration calculation unit 80 instruction value calculation unit

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // B62D 101: 00 117: 00 137: 00

Claims (1)

[Claims] 1. A means for detecting a deviation from a travel course in an unmanned vehicle that travels by autopilot while detecting a deviation from a travel course and obtaining a steering speed instruction value based on the deviation. A deviation speed calculation means for calculating the change speed (β) of the deviation amount, a deviation acceleration calculation means for calculating the change acceleration (γ) of the deviation amount, at least one of the speed β and the acceleration (γ) and the deviation An instruction value calculation unit that obtains a steering speed instruction value (w) using the amount (α), and the instruction value calculation unit includes the deviation amount (α).
At least, the deviation amount (α) and acceleration (γ)
And a steering control device for an unmanned vehicle.