JP2972015B2 - Throttle valve opening control device for autonomous vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve opening control apparatus for an automatic traveling vehicle which controls a vehicle speed to be equal to a set vehicle speed by opening and closing a throttle valve by a motor.

[0002]

2. Description of the Related Art In a golf car or an unmanned transport vehicle in a factory, a guide line embedded along a traveling course is detected by a sensor such as an induction coil provided on a vehicle body, and the vehicle speed is automatically controlled to a set vehicle speed. 2. Description of the Related Art Vehicles capable of unmanned traveling, that is, automatic traveling vehicles are known. For example, a coil (induction coil) for detecting an AC magnetic field formed by the AC current is provided on the vehicle side while an AC current is supplied to the induction wire, and a deviation from the induction line of the vehicle due to a change in the detection output of the coil. That is, there is an apparatus that detects a 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, an electric motor is often used as a driving power source to simplify vehicle speed control.

[0003]

However, in this case, however, the weight of the motor and the battery increases, causing problems such as damaging the lawn. Therefore, it is conceivable to use a gasoline engine as a driving power source instead of a motor. In this case, it is necessary to control the vehicle speed by opening and closing the throttle valve. However, since there is a large time delay between the opening and closing of the throttle valve and the change in vehicle speed, hunting of the control system is likely to occur, the vehicle speed is not stabilized, and accurate speed control is difficult.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and when an engine is used as a driving power source, hunting of a speed control system is unlikely to occur, and an automatic control system capable of accurately controlling a vehicle speed is provided. It is an object to provide a throttle valve opening control device for a traveling vehicle.

[0005]

This object according to the present invention DETAILED DESCRIPTION OF THE INVENTION, by controlling the throttle valve opening degree by the motor, an automatic vehicle for speed control to match the currently set vehicle speed (V _c) vehicle speed (V _s) , A reference opening calculating means for calculating a reference opening (θ _O ) using the set vehicle speed (V _s ), and a proportional value using the current opening (θ _c ) of the throttle valve and the current vehicle speed (V _c ). Proportional component calculating means for obtaining a component (Δθ _s );
A vehicle speed range determination means for deviation of the vehicle speed (V _c) of the set vehicle speed (V _s) to determine whether or not within a predetermined range the current,
When the deviation is outside the predetermined range, an integral component (Δθ _o ) is calculated using the set vehicle speed (V _s ). When the deviation is within the predetermined range, the integral component (Δθ) at the time when the deviation falls within the predetermined range is calculated.
₀ ) and the reference opening (θ ₀ )
And a command opening calculating means for obtaining a command opening (θ _s ) by adding the proportional component (Δθ _s ) and the integral component (Δθ ₀ ), and the throttle valve opening is calculated by the command opening (θ _s ). This is achieved by a throttle valve opening control device for an automatic traveling vehicle, characterized in that control is performed so as to match with the following.

[0006]

FIG. 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 a vehicle speed control system, FIG. 3 is an operation flowchart thereof, and FIG. FIG. 4 is a control characteristic diagram of FIG. This golf car is capable of switching between an unmanned traveling mode in which unmanned guidance is performed and a manual traveling mode in which a driver rides and steers manually.

In FIG. 1, reference numeral 10 denotes a golf car body as an automatic traveling vehicle according to the present invention. Front wheels 12, 12 as steering wheels are disposed at the front of the vehicle body 10, and rear wheels 14, 14 as driving wheels are disposed at the rear. In addition, a step 16 is provided at the rearmost portion of the vehicle body 10 so that the operator can get on the vehicle during manual operation.

Reference numeral 18 denotes a luggage mounting carrier fixed to the front portion of the vehicle body 10, on which a golf bag is placed.

A steering shaft 20 extending diagonally forward and upward toward the rear of the vehicle body is provided at the center of the vehicle body 10 in the vehicle width direction.
Are rotatably held. This steering shaft 20
A steering handle 22 is attached to the upper end of the steering wheel. 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 traveling 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 of the left and right front wheels 12 via the steering rods 30.

Reference numeral 36 denotes an electric motor for automatic steering that 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 a chain 38 (or a toothed belt). A pair of left and right guide line sensors 40 are disposed below the carrier 18, and guide lines 4 laid on the road surface along the traveling route.
2 is detected. Since the output of each sensor 40, 40 changes according to the distance from the guide wire 42, both sensors 40, 40
The deviation of the vehicle body 10 from the guidance line 40, that is, the guidance deviation can be determined based on the difference between the zero outputs.

The sensors 40, 40 may swing left and right within a predetermined angle range in synchronization with the rotation of the steering shaft 20. In this case, a change in the direction of the vehicle body 10 due to the steering of the front wheels 12 is predicted to determine the guidance deviation, and the steering accuracy by the unmanned guidance can be improved. The outputs of the sensors 40 and 40 also change depending on the inclination of the road surface or the vehicle body 10 in the left-right direction. Therefore, in order to prevent a decrease in accuracy due to this output change, three sensors 40 may be arranged at regular intervals, and the output of the three sensors 40 may be compared to determine the induced deviation.

The golf car 10 can select between an automatic mode of unmanned running and a manual mode of steering with the steering wheel 22. In the automatic mode, the motor 36 is controlled by a steering control device (not shown). That is, based on a steering angle command from another main controller, the motor 36 is rotated right or left by a predetermined rotation amount.

Next, the power system will be described. Reference numeral 50 denotes an engine mounted near the center of the vehicle body 10, and 52 denotes a rear wheel 1.
This is a drive case disposed between Nos. 4 and 14. The rotation of the crankshaft of the engine 50 is transmitted to the input shaft of the drive case 52 via a V-belt type automatic transmission 54. An electromagnetic brake 56 (FIG. 2) is interposed between the transmission 54 and the input shaft of the transmission case 52. The electromagnetic brake 56 is a spring-closed type that is excited when the vehicle is running and the brake is released, and is de-energized and the brake is applied when the main power is turned off.

The drive case 52 includes an input shaft and a rear wheel 1.
A disc brake 58 is mounted to regulate the rotation of a shaft (not shown) linked to the axle 4. The brake 58 is manually operated by the brake lever 26 of the handle 22. Therefore, the output of the engine 50 is
4 to an input shaft of a drive case 52, and to the rear wheel 14 via a reduction gear and a differential device (both not shown) in the drive case 52. The engine 50
Is mounted with a mechanical governor, and controls the opening of the throttle valve 62 of the carburetor 60 so as to limit the traveling speed.

The throttle valve 62 of the carburetor 60 connected to the engine 50 is opened and closed by either the accelerator lever 24 or the step motor 68 via electromagnetic clutches 64 and 66. That is, in the manual mode, one of the electromagnetic clutches 66 is disengaged and the other 64 is connected to transmit the rotation of the accelerator lever 24 to the throttle valve 62. In the automatic mode, one electromagnetic clutch 66 is connected, and the other 64 is turned off, and the throttle valve 62 is opened and closed by the rotation of the step motor 68. Opening of the throttle valve 62 at this time is fed back is detected by the throttle sensor 70 to the throttle valve opening control device 72, the opening degree (current opening theta _c)
Is controlled to the indicated opening degree (θ _s ).

Next, a description will be given of a throttle valve opening control device 72 for controlling the opening of the throttle valve so that the vehicle speed is set to the set vehicle speed in the unmanned traveling mode. The device 72 includes a microcomputer (CPU) 74, and the output of the throttle sensor 70 is input via an input interface (IF) 76. The throttle sensor 70 is constituted by, for example, a potentiometer whose output voltage changes according to the rotation angle.
74 is input. CPU74 has various operation functions constituted by software, the current opening degree theta _c of the throttle valve is calculated by the current position calculation unit 78.

The vehicle speed is also input to the CPU 74. For example, a vehicle speed sensor 80 that outputs a pulse in synchronization with the rotation of the rear wheel 14 is attached to the drive case 52, and the output of the sensor 80 is sent to the CPU 7 via an interface (IF) 82.
Enter 4 CPU74 now calculates the vehicle speed V _c by counting the output pulses of the sensor 72 at the current vehicle speed calculating unit 84.

Furthermore the set speed V _s is the CPU74 are inputted via the interface (IF) 86. The set vehicle speed V _s of which are set by another control device based on the travel pattern of the automatic driving mode. CPU7
In 4 of these set vehicle speed V _s, is computed by the computing unit 88 the reference opening theta _o using the current vehicle speed V _c and the current opening theta _c (step 100 of FIG. 3). This operation is conducted by a predetermined equation, for example, obtained by _{θ o = f (V s)} . Function f (V _s) as V _s of the linear function f (V
_s ) = k ₁ V _s ² + k ₂ can be used. Here k
₁ and k ₂ are positive constants.

[0020] The proportional component [Delta] [theta] _s with the CPU74 then the current opening theta _c and the current vehicle speed V _c, calculated by _{Δθ s = g (θ c,} V c) ( Fig. 3, step 102). This calculation is performed by the calculation unit 90.

The CPU 74 further obtains the integral component Δθ _o by the calculation section 92 (step 104). That is, it is determined by Δθ _o = h (V _s ). Incidentally calculation of the integral component [Delta] [theta] _o is a predetermined range the current vehicle speed V _c is centered on the set vehicle speed V _s that is, performed only when you are out of the range of _{V 1 ≦ V c ≦ V 2} ( step 106, 108 ), when in this range for holding the integral component [Delta] [theta] ₀ when entering this range (step 1
10).

The reference opening θ _o , the proportional component Δθ _s , and the integral component Δθ _o obtained as described above are added in the arithmetic unit 94 to obtain the indicated opening θ _s (step 11).
2). That instruction opening theta _s is determined by _{θ s = θ o + Δθ s} + Δθ o.

The command opening θ _s obtained in this manner is output to the driver 9 via the output interface (IF) 96.
8 is input. The driver 98 is currently opening theta _c of the throttle valve 62 controls the stepping motor 68 so that the instruction opening theta _s. The above operation is repeated until a stop signal is input (step 114).

FIG. 4A shows control characteristics at the time of starting. As the set vehicle speed V _s type, for example, 10 km / h, the lower limit vehicle speeds V ₁ to a range of ± 1km / h around the set vehicle speed V _s
= 9 and the upper limit vehicle speed V ₂ = 11. V _{1 in the} CPU 74
The range of ~V ₂ calculates the integral component [Delta] [theta] _o as described above, within the range retaining the [Delta] [theta] _0.

[0025] Thus, when the set vehicle speed V _s (= 10) is input, a first reference opening theta _o For example, θ _o = k ₁ · ₁
0 ² + k ₂ (step 100). Then, a proportional component Δθ _s = g (θ _c , V _c ) is obtained (step 10).
2). Then because the current vehicle speed V _c is outside the range of V ₁ ~V ₂ (step 106), the integral component [Delta] [theta] _o = seeking h (V _s) (step 104), obtains the instruction opening theta _s (step 114 ).

[0026] In the next operation cycle, since the current opening theta _c is open toward the indication opening theta _s, theta _c and the current vehicle speed V _c is increased. This new θ _c , V _c
Is used to repeat the operations of steps 100 to 112. Thus while until current vehicle speed V _c is in the range V ₁ ~V ₂ increases the integral component [Delta] [theta] _o gradually, reference opening theta _o, proportional component [Delta] [theta] _s will be gradually decreased, instructing opening theta _s is It changes. That is, in this speed range, the proportional component (P
Component) and the integral component (I component) are added to perform proportional integral control (PI control). In FIG. 4A, PI
Indicates the range of this PI control. Such current vehicle speed V _c to the quickly increasing.

The vehicle speed V _c when is in the range V ₁ ~V ₂ integral component [Delta] [theta] _o at this time is held (step 110). Therefore, the integral component (I component) of the set opening degree θ _s becomes constant, and proportional control (P control) is performed. Stabilized to the set vehicle speed V _s gradually as described above.

FIG. 4B shows the control characteristics at the time of climbing. That it is, reaches the slope during running in set vehicle speed V _s = 10km / h, in order to load increases the current vehicle speed V _c is the range V ₁ ~V
Deviate from ₂ . Enters the proportional integral control from this for proportional control (P) (PI), promptly instructs opening theta _s correction is performed, it is returned to the set vehicle speed V _s.

The predetermined range V including the thus set vehicle speed V _s
1 ~V is in ₂ stable control because performing proportional control, also quick response because performs proportional integral control is obtained outside this range V ₁ ~V _2.

[0030]

According to the present invention as described above, by the proportional control, performs proportional integral control and outside this range when containing the vehicle within a predetermined deviation range including the set vehicle speed V _s, the throttle valve opening Because it controls the degree θ _c ,
Within this range, stable hunting-free control is possible,
Outside this range, quick and responsive control becomes possible. Therefore, the vehicle speed can be stably controlled with high accuracy.

[Brief description of the drawings]

FIG. 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 the vehicle speed control system;

FIG. 3 is a flowchart of the operation.

FIG. 4 is a control characteristic diagram at the time of starting and climbing.

[Explanation of symbols]

 72 Throttle valve opening control device 74 CPU 88 Reference opening calculating section 90 Proportional component calculating section 92 Integral component calculating section 94 Instructed opening calculating section 106, 108 Vehicle speed range determination step

Continuation of the front page (56) References JP-A-1-153344 (JP, A) JP-A-63-22736 (JP, A) JP-A-61-285139 (JP, A) JP-A-1-20239 (JP, A) , A) JP-A-53-85287 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 29/02 301 F02D 41/14 320

Claims (1)

(57) [Claims] 1. An automatic traveling vehicle in which the current vehicle speed (V _c ) is controlled to match the set vehicle speed (V _s ) by controlling the throttle valve opening degree by a motor, and the set vehicle speed (V _s ) is controlled. proportional component for obtaining the reference opening calculating means for calculating a reference opening (θ _O), the current degree of opening (theta _c) the current vehicle speed (V _c) and the proportional component with a throttle valve ([Delta] [theta] _s) using and calculation means, the set vehicle speed and the vehicle speed range determination means for deviation from the set vehicle speed for the current vehicle speed (V _c) (V _s) it is determined whether or not within a predetermined range, when said difference is outside a predetermined range Integral calculation means for calculating an integral component (Δθ _o ) using (V _s ) and holding the integral component (Δθ ₀ ) when the deviation falls within the predetermined range; the addition of the (theta ₀₎ and the proportional component ([Delta] [theta] _s) and the integral component ([Delta] [theta] ₀₎ And a instruction opening calculating means for calculating示開degree (θ _s), the throttle valve opening automatic vehicle of a throttle valve and controls so as to match this instruction opening (theta _s) Opening control device.