JPH09130920A - Vehicle speed controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the comfortableness from deteriorating even if a vehicle turns abruptly when it is traveling at high speed. SOLUTION: A joy stick input section 71 calculates the back/forth component and left/right component of tilt angle from the tilt angle of a joy stick 11 and a command vehicle speed calculating section 72 calculates command vehicle speeds VL, VR for left and right wheels. A command vehicle speed corrective calculation section 74 calculates the absolute value of speed difference |VL-VR|, determines a deceleration coefficient using the absolute value and then calculates corrected command vehicle speeds VL', VR' for the left and right wheels using the command vehicle speeds VL, VR and the deceleration coefficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle speed control device for a vehicle in which left and right drive wheels are individually driven.

[0002]

2. Description of the Related Art Conventionally, a joystick is often used as a traveling instruction device for an electric wheelchair. This travel instruction device is capable of tilting the joystick forward, backward, leftward and rightward, and allows the wheelchair to travel in the tilting direction and controls the traveling speed according to the tilting angle. That is, when the joystick is tilted shallowly, it travels at a slow speed, and when it is tilted deeply, it travels at a high speed. Further, by operating the joystick, it is possible to move forward, reverse, turn, or rotate on the spot.

Since an electric wheelchair is used by a physically handicapped person, the maximum speed of the electric wheelchair is restricted to the extent that a healthy person can walk at most. Therefore, when the user becomes accustomed to driving an electric wheelchair, the joystick is tilted to the limit and the user often runs at the maximum speed.

[0004]

However, when the joystick is suddenly operated to make a turning movement while the vehicle is traveling at the maximum speed, no matter how the maximum speed is the walking speed of a healthy person, the turning radius is If it is small, a large centrifugal force will be generated, which may deteriorate the riding comfort.

The present invention solves the above problems, and an object of the present invention is to provide a vehicle speed control device which prevents deterioration of the riding comfort even when the vehicle suddenly turns while traveling at high speed.

[0006]

According to the present invention, in a vehicle having left driving means for rotationally driving a left driving wheel and right driving means for rotationally driving a right driving wheel, the left and right driving wheels are the same. The first operation of rotationally driving the wheel at the same wheel speed in the same direction and the second operation of rotationally driving the left and right driving wheels at respective predetermined wheel speeds in the opposite directions can be performed individually or simultaneously, and Operating means for instructing the command wheel speed of each drive wheel according to the operation amount of each operation, and each command wheel speed according to the magnitude of the absolute value of the difference between the command wheel speeds of the instructed drive wheels. And a drive control means for controlling the left drive means and the right drive means to rotationally drive the drive wheels at the corrected command wheel speeds. (Claim 1).

According to this structure, the command wheel speeds of the left and right drive wheels are instructed by the operating means in accordance with the operation amount of the first operation and the operation amount of the second operation, and each instructed drive wheel is driven. Depending on the magnitude of the absolute value of the command wheel speed difference of
The correction means reduces the absolute value of each commanded wheel speed. Then, the left drive means and the right drive means are controlled to rotationally drive the left and right drive wheels at each of the corrected command wheel speeds. As a result, when the absolute value of the difference between the command wheel speeds of the drive wheels is large due to the operation performed by the operating means, that is, when the vehicle has a small turning radius, the command wheel speeds are corrected to be small and the centrifugal force generated in the vehicle is reduced. The power decreases.

Further, in a vehicle having a left drive means for rotationally driving the left drive wheel and a right drive means for rotationally driving the right drive wheel, the left and right drive wheels are rotationally driven in the same direction at the same wheel speed. The first operation to perform and the second operation to rotate the left and right drive wheels in opposite directions to each other at predetermined wheel speeds are possible individually or simultaneously, and depending on the operation amount of each operation. Operating means for instructing the command wheel speed of each drive wheel, acceleration calculating means for calculating the centrifugal acceleration of the vehicle using the instructed wheel speed of each drive wheel, the calculated centrifugal acceleration and Comparing means for comparing with a set value, and correcting means for correcting the commanded wheel speed of each drive wheel so that the centrifugal acceleration matches the set value when the centrifugal acceleration is larger than the set value. This corrected the commanded wheel speed is obtained by a drive control means for controlling the left drive unit and right drive unit to drive the rotation of each drive wheel (claim 2).

According to this structure, the command wheel speeds of the left and right drive wheels are instructed by the operating means in accordance with the operation amount of the first operation and the operation amount of the second operation, and each of the instructed drive wheels is instructed. The centrifugal acceleration of the vehicle is calculated using the commanded wheel speed of. When the calculated centrifugal acceleration is larger than a preset value, the command wheel speed of each drive wheel is corrected so that the centrifugal acceleration matches the set value. And
The left drive means and the right drive means are controlled to rotationally drive the left and right drive wheels at each of the corrected command wheel speeds. As a result, the centrifugal acceleration generated in the vehicle is maintained below the set value even when the vehicle has a small turning radius due to the operation performed by the operating means, so that the comfort of the vehicle is reliably prevented from being degraded.

Further, the operation means reduces the weighting of the operation amount of the second operation as compared with the operation amount of the first operation to instruct each of the command wheel speeds (claim 3). ).

According to this structure, the command wheel speed of each drive wheel is instructed by reducing the weighting of the operation amount of the second operation as compared with the operation amount of the first operation. The absolute value of the difference between the command wheel speeds of the drive wheels is reduced as compared with the operation amount. Therefore, since the traveling turning radius of the vehicle does not become small, a large centrifugal force is not generated in the vehicle, and the reduction in the riding comfort of the vehicle is further reliably prevented.

Further, in the vehicle speed control device according to any one of claims 1 to 3, a radius calculation for calculating a traveling turning radius of the vehicle by using a command wheel speed of each of the drive wheels instructed by the operating means. The correction means corrects the commanded wheel speed of each of the drive wheels so that the traveling turning radius does not change (claim 4).

According to this structure, the command wheel speeds of the respective drive wheels are corrected so that the vehicle turning radius is not changed by the operation performed by the operating means, so that the operability of the vehicle is not deteriorated and the vehicle operability is reduced. Ride comfort does not deteriorate.

Further, in a vehicle having a left drive means for rotationally driving the left drive wheel and a right drive means for rotationally driving the right drive wheel, the left and right drive wheels are rotationally driven in the same direction at the same wheel speed. The first operation to perform and the second operation to rotate the left and right drive wheels in opposite directions to each other at predetermined wheel speeds are possible individually or simultaneously, and depending on the operation amount of each operation. Operation means for instructing the command wheel speed of each drive wheel, and drive control means for controlling the left drive means and the right drive means so as to rotationally drive each drive wheel at the instructed wheel speed of each drive wheel. The operating means reduces the weighting of the operation amount of the second operation as compared with the operation amount of the first operation and indicates the command wheel speed of each drive wheel (claim). Item 5).

According to this structure, the command wheel speeds of the left and right drive wheels are instructed by the operating means in accordance with the operation amount of the first operation and the operation amount of the second operation. Then, the left drive means and the right drive means are controlled to rotationally drive the left and right drive wheels at the instructed wheel speeds. At this time,
Since the command wheel speed of each drive wheel is instructed by reducing the weighting of the operation amount of the second operation as compared with the operation amount of the first operation, each drive wheel is compared with the operation amount performed by the operating means. The absolute value of the difference between the commanded wheel speeds is reduced. Therefore, since the traveling turning radius of the vehicle does not become small, a large centrifugal force is not generated in the vehicle.

[0016]

First, the principle of the present invention will be described with reference to FIG. FIG. 12 is a schematic diagram for explaining the speed and the turning radius of the drive wheels when the vehicle turns.

In the figure, V _L is the wheel speed of the left drive wheel (hereinafter referred to as the left wheel vehicle speed), V _R is the wheel speed of the right drive wheel (hereinafter referred to as the right wheel vehicle speed), and V _C is the vehicle speed. , R _L is the turning radius of the left drive wheel, R _R is the turning radius of the right drive wheel, R _C
Is the vehicle turning radius and TREAD is the tread of the vehicle. Since the vehicle in FIG. 12 shows a state in which turning to the right, V _L> V _R, an _{R L>} R R.

Generally, the centrifugal force generated in a vehicle is

[0019]

[Equation 1] Centrifugal force = weight × (traveling speed) ² / traveling turning radius Therefore, even if the vehicle travels at the same speed, a greater centrifugal force is generated as the traveling turning radius is smaller.

Further, from FIG.

[0021]

[Equation 2] TREAD = _{RL- RR}

[0022]

[Formula 3] V _L / V _R = R _L / R _R

[0023]

[Equation 4] R _C = R _R + TREAD / 2

[0024]

## EQU5 ## Each equation of V _C = (V _L + V _R ) / 2 is obtained.

From the above equations 2 and 3,

[0026]

[6] _{TREAD = R R × V L /} V R -R R = R R × (V L -V R) / V R is obtained by modifying this equation,

[0027]

Equation 7] _{R R = V R × TREAD /} (V L -V R) is obtained. Substituting this Equation 7 into Equation 4 above,

[0028]

Equation 8] _{R C = R R + TREAD /} 2 = V R × TREAD / (V L -V R) + TREAD / 2 = TREAD × {1/2 + V R / (V L -V R)} is obtained.

Now, let us consider a case where the vehicle travels forward at a constant speed, that is, when V _C is constant and V _L and V _R ≧ 0.

According to the above equation 8, the traveling turning radius R _C is
Determined by the _{V R / (V L -V R} ). On the other hand, since the vehicle speed V _C is constant, (V _L + V _R ) is constant from Equation 5 above. Therefore, the left and right drive wheels (hereinafter, referred to as the left and right wheels) The fact that the vehicle speed difference (V _L -V _R) is increased, the right wheel speed V
_Since it means that _R decreases, V _R / (V _L −
V _R) is reduced.

Therefore, the larger the vehicle speed difference ( _VL -VR) between the left and right wheels is, the smaller the traveling turning radius _RC becomes. Therefore, the centrifugal force generated in the vehicle is increased from the equation ( ₁ ). Note that, contrary to the case of FIG. 12, the same applies when V _R > V _L of turning left.

Therefore, according to the present invention, by utilizing the above characteristics of the vehicle, even if the operating means issues a command to increase the absolute value of the vehicle speed difference between the left and right wheels, the drive wheels are driven according to the command. Instead, the speed of each driving wheel is automatically reduced to prevent the ride quality from deteriorating even when the vehicle is turning while the command from the operating means remains at the maximum speed.

An embodiment of an electric wheelchair to which the present invention is applied will be described below. FIG. 1 is a block diagram showing the control configuration of the first embodiment.

This electric wheelchair includes an operation panel 1, a power supply unit 2, motors 3L and 3R, relays 4L and 4R, motor control units 5L and 5R, a control board 6, and C.
And PU7.

The operation panel 1 has a joystick 11 and a main switch 12 which are operated by an occupant. The joystick 11 constitutes an operating means for operating the running of the electric wheelchair, and can be tilted in a 360 ° direction around the base of the joystick as a fulcrum. The tilting direction indicates the traveling direction of the vehicle. The speed of the vehicle is instructed by the tilt angle, which is the depth of tilt, and the operation amount, that is, the operation signal corresponding to the front-back direction component and the operation signal corresponding to the left-right direction component of the tilt angle are output. Is configured.

The main switch 12 is provided between the power supply section 2 and the control board 6 and operates to turn on / off the power supply to the control board 6. The power supply unit 2 is composed of a storage battery or the like and supplies power to each unit.

The motor 3L, the relay 4L and the motor control unit 5L constitute a left drive means for driving the left drive wheel of the electric wheelchair, and the motor 3R, the relay 4R and the motor control unit 5R drive the right drive wheel. It constitutes a right driving means for driving the wheels.

The motors 3L and 3R rotate the left and right wheels of the electric wheelchair, and are connected to motor control units 5L and 5R via relays 4L and 4R, respectively. Vehicle speed sensors 31L and 31R are provided in the motors 3L and 3R, respectively. Vehicle speed sensor 31L,
The reference numeral 31R is composed of a pulse encoder, an optical sensor, etc., and detects the rotation speed of the motor and outputs a pulse signal corresponding to the rotation speed.

The relays 4L and 4R have common contacts 41L and 41R, ON contacts 42L and 42R, and OFF contacts 43L and 43R, respectively, which are switched by the CPU 7.
Is controlled by the In FIG. 1, each of the relays 4L and 4R is in the ON state.

The motor control units 5L and 5R supply drive currents to the motors 3L and 3R, respectively, and the supply current levels thereof are controlled by the CPU 7.

The control board 6 includes input / output interfaces (hereinafter referred to as IFs) 61 to 64, a CPU.
7, a memory 8 and the like are provided, and the CPU 7 has a joystick input unit 71, a command vehicle speed calculation unit 72, and a vehicle speed calculation unit 7
3, a command vehicle speed correction calculation unit 74 and a PWM wave calculation unit 75 are provided. The memory 8 stores a control program and various data such as a maximum speed Vmax and a set value Gmax described later.

The IF 61 is provided between the joystick 11 and the joystick input section 71, and the IF 62
Is the motor controller 5L, 5R and the PWM wave calculator 75
The IF 63 is interposed between the relays 4L and 4R and the command vehicle speed correction calculator 74, and the IF 64 is interposed between the vehicle speed sensors 31L and 31R and the vehicle speed calculator 73. The input / output processing of various signals is performed.

The joystick input section 71 has an IF6
A signal relating to the tilt direction and tilt angle of the joystick 11 is A / D converted and input via 1. The joystick input unit 71 calculates the front-back direction component and the left-right direction component of the tilt angle from this input signal, and the command vehicle speed calculation unit 7
2 is output. These values are positive when the joystick 11 is tilted forward (to the right),
Negative when tilted backward (to the left).

The command vehicle speed calculation unit 72 tentatively calculates the command vehicle speed V _{L for} the left wheel and the command vehicle speed V _R for the right wheel from the front-back direction component and the left-right direction component of the tilt angle of the joystick 11, and the command vehicle speed correction calculation unit. It outputs to 74.

Here, referring to FIG. 2, the command vehicle speed calculation unit 7
Calculation of the left wheel vehicle speed V _L and the right wheel vehicle speed V _R in 2 will be described. FIG. 2 is an explanatory diagram showing the tilting direction and tilting angle of the joystick 11, and Rmax represents the stroke when the tilting angle is maximum.

[0046]

[Formula 9] V _L = F ₁ (Front-back direction component of tilt angle, left-right direction component of tilt angle) V _R = F ₂ (Front-back direction component of tilt angle, left-right direction component of tilt angle) Command vehicle speed calculation unit 72 , Left-wheel vehicle speed _VL and right-wheel vehicle speed V
_As shown in the above equation 9, _R is calculated by the functions F ₁ and F ₂ having the front-back direction component and the left-right direction component of the tilt angle of the joystick 11 as parameters.

In the case where the joystick 11 is tilted in the + -direction of the front-rear direction and the left-right direction component = 0, that is, in the case of FIG. 2, the functions F ₁ and F ₂ are set so that V _L = V _R. As a result, the electric wheelchair moves forward.

When the joystick 11 is tilted in the + direction including the front-back direction component and the left-right direction component, that is, in the case of FIG. 2, the functions F ₁ and F ₂ have V _L > V _L >.
It is set to V _R , which causes the electric wheelchair to turn to the right.

Further, when the joystick 11 is tilted in the + direction of the left and right direction and the longitudinal component = 0, that is, in the case of FIG. 2, the functions F ₁ and F ₂ have opposite rotational directions of the left and right wheels. becomes, the absolute value of the velocity is equal, i.e. V _L = -V _R> 0 and is set to be, whereby electric wheelchair rotates on the spot.

In FIG. 3, when the joystick 11 is rotated from the front (+) of the front-back direction component to the right (+) of the left-right direction component at the maximum tilt angle, as shown in FIG. component values X left wheel speed V _L for (maximum 100), the right wheel speed V _R, the vehicle speed difference between the left and right wheels (V _L -V _R)
FIG. 6 is a diagram showing a vehicle speed V _C = (V _L + V _R ) / 2.

In FIG. 3, the functions F ₁ and F ₂ of the above equation 9 are

[0052]

## EQU10 ## V _L = F ₁ (Y, X) = Y + pX V _R = F ₂ (Y, X) = Y−pX, and the maximum speed of V _L and V _R is 100. In addition,
p is a coefficient representing the weighting of the left-right direction component with respect to the front-back direction component. If p = 1/2 in the above formula 10, from X ² + Y ² = Rmax ² ,

[0053]

Equation 11] _{V L = Y + 1 / 2X} = √ (Rmax 2 -X 2) + 1 / 2X V R = Y-1 / 2X = √ (Rmax 2 -X 2) -1 / 2X is achieved. FIG. 3 shows these V _L and V _R.

In FIG. 3, the point A has V _R = 0 and the right 90
A turn is shown, and point B is V _L = −V _R = 50, indicating a turn on the spot. In the range of X = 0 to X _1, left wheel speed V _L is the maximum speed 10 the calculated value shown by a broken line shown by a solid line
Limited to 0.

[0055] As shown in FIG. 3, with the calculated result of the command vehicle speed calculating unit 72, a vehicle speed difference between the left-right direction component X increases right and left wheels (V _L -V _R) is monotonically increasing.

Returning to FIG. 1, the vehicle speed calculation unit 73 uses the IF6
The actual speeds of the left and right driving wheels, that is, the actual vehicle speeds v _L and v _R are calculated by using the pulse signals input from the vehicle speed sensors 31L and 31R via the controller 4, and these are calculated by the command vehicle speed correction calculation unit 74 and the PWM. It is output to the wave calculation unit 75.

The command vehicle speed correction calculation unit 74 corrects the left wheel vehicle speed V _L and the right wheel vehicle speed V _R calculated by the command vehicle speed calculation unit 72 according to the procedure described below to correct the left wheel corrected command vehicle speed V _L '. And the correction command vehicle speed V _R ′ for the right wheel and the calculated correction command vehicle speed V _L ′, V _R ′ for the left and right wheels are output to the PWM wave calculation unit 75.

First, from the left wheel vehicle speed V _L and the right wheel vehicle speed V _R calculated by the command vehicle speed calculator 72, the absolute value of the vehicle speed difference |
V _L −V _R | is calculated, and this value is given by the function G ₁
To calculate the deceleration coefficient R _G.

[0059]

## EQU12 ## R _G = G ₁ (| V _L −V _R |) FIG. 4 is a diagram showing an example of the function G ₁ . As shown in FIG. 4, the function G ₁ is the vehicle speed difference | V _L -V _R | When larger, the deceleration coefficient R _G is set to be smaller.

Next, the command vehicle speed V _L of right and left wheels, by substituting V _R and the deceleration coefficient R _G to a function H _1, H ₂ shown in the following Expression 13, the correction command vehicle speed V _L of the left wheel 'and the right wheel Correction command vehicle speed V
Calculate _R '.

[0061]

Equation 13] _{V L '= H 1 (V} L, R G) V R' = H 2 (V R, R G) This function H _1, H _{2 is, V L '<V L,} V R'< is set in such a way that V _R. An example of the functions H ₁ and H ₂ is shown in Expression 14 below.

[0062]

In Equation 14] _{V L '= V L × (} k × R G) V R' = V R × (k × R G) number 14, k is a constant, it may be k = 1.

Even if the command vehicle speeds V _L and V _R for the left and right wheels are corrected to the corrected command vehicle speeds V _L ′ and V _R ′ using this equation 14, the traveling turning radius R _C changes due to the relationship of the above equation 8. do not do. Therefore, the traveling course is decelerated without changing.

The above function G ₁ is 0 as shown in FIG.
≦ | V _L -V _R | in the range of _{≦ d1, V L '= V} L, V R' =
It is set such that V _R. This is because the handicapped passenger has a delicate joystick 11
Can not be operated, for example, because I want to go straight, I try to operate the joystick 11 forward, but if I accidentally operated a little in the left and right directions, a command vehicle speed difference between the left and right wheels will occur and This is to prevent the commanded vehicle speed from being decelerated and corrected to deteriorate the riding comfort.

Returning to FIG. 1, the commanded vehicle speed correction calculator 7 is used.
4 is the calculated correction command vehicle speed V _L ', V for the left and right wheels.
_When the absolute value of R'exceeds a preset maximum speed Vmax, the maximum speed Vmax is limited. That is, the correction command vehicle speed V _L of the calculated left wheel 'is | V _L' |> Vmax If, | V _L '| = a Vmax, the calculated right wheel correction command vehicle speed V _R' is | V _R '|> Vmax if, | V _R '| = Vmax
And

Further, the command vehicle speed correction calculation unit 74 monitors the actual vehicle speeds v _L and v _R input from the vehicle speed calculation unit 73 in order to limit the vehicle speed of the left and right wheels to the maximum speed Vmax.

[0067] Further, command vehicle speed correction calculation unit 74, when the correction command vehicle speed V _L of left and right wheels ', V _R' calculation result of 0, i.e., stopping the both or either of the drive wheels, IF6
An off signal is output to the relays 4L and 4R, which are to be stopped via 3, to turn off the relays, and the corresponding motors 3L and 3R
The current supply to R is cut off and stopped. On the other hand, the correction command vehicle speed V _L of left and right wheels ', V _R' when the calculation result of the non-zero, the corresponding relay 4L through IF63, and outputs an ON signal is turned on 4R.

The PWM wave calculation unit 75 has the actual vehicle speeds v _L and v _R input from the vehicle speed calculation unit 73 and the commanded vehicle speed correction calculation unit 7.
Correction command vehicle speed V _L of right and left wheels inputted from 4 ', V _R' from the corrected command speed and the actual vehicle speed deviation (V _L '-v _L),
(V _R '-v _R) is calculated and the function D _L shown in the following Expression 15, D
_The duty ratios K _L and K _R are calculated using _R.

[0069]

## EQU15 ## K _L = D _L (V _L ', Δ (V _L ' -v _L )) K _R = D _R (V _R ', Δ (V _R ' -v _R )) The above functions D _L , D _R is set so as to obtain the correction command vehicle speed and the duty ratio according to the deviation between the correction command vehicle speed and the actual vehicle speed.

Then, the PWM wave calculation section 75
A PWM wave control signal corresponding to the duty ratios K _L and K _R is output to the motor control units 5L and 5R via the
The drive current level supplied to L and 3R is controlled. As a result, the rotation speeds of the motors 3L and 3R, that is, the vehicle speeds of the left and right drive wheels are controlled.

Next, the operation of the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the operation procedure of the first embodiment.

First, the front-rear direction component and the left-right direction component of the tilt angle are calculated from the tilt angle signal of the joystick 11 and input to the command vehicle speed calculation unit 72 (step S1), and then the command vehicle speeds V _L , V of the left and right wheels. _R is calculated (step S2), and the absolute value of the vehicle speed difference from the calculated value | V _L -V _R | is calculated (step S3), and the absolute value using a deceleration coefficient R _G is calculated (step S4) , the command vehicle speed V _L, V _R
And correction command vehicle speed V _L 'of the left and right wheels using the deceleration coefficient R _G ,
V _R 'is calculated (step S5).

Next, the actual vehicle speed v _L of the right and left wheels, v _R is calculated (step S6), and then correction command vehicle speed and actual vehicle speed deviation _{(V L '-v L),} (V R' -v R ) Is calculated (step S7), and using these, the duty ratio K _{L of} the PWM wave,
K _R is calculated (step S8), and the duty ratio K _L, PWM wave control signal corresponding to K _R is output (step S9).

Then, the system is terminated, that is, if the main switch 12 is off (YES in step S10).
S), and if the main switch 12 is not off (NO in step S10), the process returns to step S1 and the above operation is repeated.

[0075] Thus, according to the first embodiment, the command vehicle speed V _L of right and left wheels, the V _R, the absolute value of the vehicle speed difference | V _L -
V _R | correction command vehicle speed V _L which is decelerated in accordance with the ', V _R' since so as to correct, even with turning by operating the tilting angle of the joystick 11 to the maximum speed, prevent the ride comfort deterioration can do. Also, each command vehicle speed V _L, V _R
Is corrected so that the traveling turning radius does not change, so that the operation of the joystick 11 and the actual traveling of the electric wheelchair can be matched with each other, and thus the operability can be prevented from being deteriorated.

The deceleration coefficient R _G is not calculated by using the function G ₁ as described above, but table data prepared in advance is stored in the memory 8 and the absolute value of the vehicle speed difference is calculated. According to the above, the table data may be referred to and obtained.

FIG. 6 is a block diagram showing the control configuration of the second embodiment of the electric wheelchair to which the present invention is applied. The same components as those in the first embodiment are designated by the same reference numerals,
Only the differences will be described.

In the second embodiment, the joystick input section 71 also outputs the horizontal component of the tilt angle of the joystick 11 to the command vehicle speed correction calculation section 74.

Then, the command vehicle speed correction calculation unit 74 replaces the absolute value | V _L -V _R | of the vehicle speed difference between the left and right wheels with the absolute value of the horizontal component of the tilt angle of the joystick 11 as shown in the following formula 1.
The deceleration coefficient R _G is calculated by substituting it into the function G ₂ shown in FIG.

[0080]

## EQU16 ## R _G = G ₂ (| horizontal component of tilt angle |) FIG. 7 is a diagram showing an example of the function G ₂ . As shown in FIG. 7, the function G ₂ is set so that the deceleration coefficient R _G becomes smaller as the absolute value of the horizontal component of the tilt angle of the joystick 11 becomes larger. Similar to the function G ₁ shown in FIG. _{4, 0 ≦ | V L -V} R | in the range of _{≦ D1, V L '= V} L, V R' is set to be = V _R There is.

Even in this case, the absolute value of the vehicle speed difference between the left and right wheels |
Since V _L −V _R | is determined only by the absolute value of the horizontal component of the tilt angle of the joystick 11, the deceleration coefficient R _G can be similarly obtained. Therefore, similarly to the first embodiment, the traveling turning radius R _C does not change and the traveling course is decelerated without changing.

Next, the operation of the second embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the operation procedure of the second embodiment.

Steps S21 and S22 are the same as steps S1 and S2 in FIG. Following step S22, the joystick 11 calculated in step S21
Deceleration coefficient R using the absolute value of the left-right direction component of the tilt angle of
_G is calculated (step S23). Subsequent step S2
4 to S29 are the same as steps S5 to S10 in FIG.

[0084] Thus, according to the second embodiment, the command vehicle speed V _L of right and left wheels, the V _R, corrected command vehicle speed V _L which is decelerated in accordance with the absolute value of the horizontal direction component of the tilt angle of the joystick 11 ' , V _R ', the deterioration of riding comfort can be prevented even when the joystick 11 is turned to the maximum speed by turning the tilt angle. Also, each command vehicle speed V _L, the V _R, since the travel turning radius is corrected so as not to be changed, it is possible to align the running of the actual electric wheelchair and operation of the joystick 11, whereby, the operability The decrease can be prevented.

Note that the deceleration coefficient R _G is not calculated by using the function G ₂ as described above, but table data prepared in advance is stored in the memory 8 and the absolute value of the vehicle speed difference is stored. According to the above, the table data may be referred to and obtained.

FIG. 9 is a block diagram showing the control configuration of the third embodiment of the electric wheelchair to which the present invention is applied. The same components as those in the first embodiment are designated by the same reference numerals,
Only the differences will be described.

The third embodiment differs from the first embodiment in that
A left and right component weighting calculation unit 76 is newly provided between the joystick input unit 11 and the command vehicle speed calculation unit 72, while the command vehicle speed correction calculation unit 74 is removed.

The left / right component weighting calculation unit 76 substitutes the left / right direction component of the tilt angle calculated by the joystick input unit 71 into the function f shown in the following formula 17 for correction. At the same time, the correction value and the front-back direction component are output to the command vehicle speed calculation unit 72.

Then, the command vehicle speed calculator 72 calculates the functions F ₁ and F from the correction values of the left and right components of the tilt angle and the front and rear components obtained by the left and right component weighting calculator 76, as shown in the following Expression 17. _The command vehicle speeds V _L and V _R are calculated by 2 and the calculated values are output to the PWM wave calculation unit 75.

[0090]

[Formula 17] V _L = F ₁ (front-back component of tilt angle, f (left-right component of tilt angle)) V _R = F ₂ (front-back component of tilt angle, f (left-right component of tilt angle)) The function f is set so that the weighting of the tilting angle of the joystick 11 with respect to the left-right direction component is lower than that of the front-back direction component. Lateral direction component of the tilt angle, the command vehicle speed V _L of right and left wheels, the vehicle speed difference V _R | V _L -V _R | is intended to cause, by the function f, the vehicle speed difference |
V _L -V _R | is to be reduced.

Further, the command vehicle speed calculation section 72 has a maximum speed Vmax limiting function of the command vehicle speed which the command vehicle speed correction calculation section 74 of the first embodiment has, an actual vehicle speed v _L input from the vehicle speed calculation section 73, It has a v _R monitoring function and an ON / OFF signal output function to the relays 4L and 4R.

Next, the operation of the third embodiment will be described with reference to FIG. FIG. 10 is a flowchart showing the operation procedure of the third embodiment.

The step S41 is the step S of FIG.
The same as 1. Following step S41, step S
The left-right direction component of the tilt angle of the joystick 11 calculated in 41 is substituted into the function f, and weighting calculation of the left-right direction component is performed (step S42).

Next, the command vehicle speeds V _L and V _{R for} the left and right wheels are calculated from the result of the weighting calculation and the front-back direction component of the tilt angle of the joystick 11 (step S43).
The actual vehicle speeds v _L and v _{R of the} left and right wheels are calculated (step S4
4), then the command vehicle speed and actual vehicle speed deviation (V _L -v _L),
(V _R -v _R) is calculated (step S45).

The following steps S46 to S48 are the same as those in FIG.
The same as steps S8 to S10.

As described above, according to the third embodiment, the weighting of the tilting angle of the joystick 11 with respect to the left-right direction component is made lower than the front-back direction component and is substituted into the functions F ₁ and F _2. speed difference command vehicle speed V _L, V _R of wheels | V _L -V _R | is reduced, thereby, even when turning by operating the tilting angle of the joystick 11 to the maximum speed, prevent the ride comfort deterioration can do. Further, since only the weighting of the tilt angle in the left-right direction component is reduced, the calculation time of the CPU 7 can be shortened and the control program can be realized with a simple configuration.

Next, a fourth embodiment of the electric wheelchair to which the present invention is applied will be described. The control configuration of the fourth embodiment is the same as that of the first embodiment shown in FIG. 1, but the correction procedure of the command vehicle speed correction calculation unit 74 is different, and this difference will be described.

The command vehicle speed correction calculating section 74 calculates the centrifugal acceleration G of the vehicle according to the procedure described below, and when the value exceeds the preset set value Gmax, this centrifugal acceleration G is set to the above-mentioned setting. value command vehicle speed V _L of right and left wheels so as to Gmax, V _R correction command vehicle speed correcting the V _L ', V _R' and calculates a.

That is, first, using the command vehicle speeds V _L and V _R for the left and right wheels calculated by the command vehicle speed calculation unit 72, the above equation 5 is used.
The vehicle speed V _C is calculated by the following equation, and the traveling radius R _C of the vehicle is calculated by the above equation 8.

[0100]

G = (V _C ) ² / R _C Next, the centrifugal acceleration G of the vehicle is calculated by the above equation 18 using the vehicle speed V _C and the vehicle turning radius R _C. Note that from Equation 1 above, it can be seen that the centrifugal acceleration G is calculated by Equation 18 above.

Then, the calculated centrifugal acceleration G is G>
When Gmax, the correction command vehicle speed V _L ',
V _R 'is calculated, and when G ≤ Gmax, V _L ' = V _L , V _R '=
And V _R.

[0102]

Equation 19] _{V L '= √ (Gmax /} G) × V L V R' = √ (Gmax / G) × V R The above setting value Gmax is the maximum value that does not impair the riding comfort when the turning Is set to.

In the fourth embodiment, the command vehicle speeds V _L and V _R for the left and right wheels are corrected using the equation (19) to correct the command vehicle speeds V _L 'and V _R '.
To be corrected, the relationship of the number 8, the travel turning radius R _C
Does not change. Therefore, similarly to the first embodiment, the traveling course is decelerated without changing.

Next, the operation of the fourth embodiment will be described with reference to FIG. FIG. 11 is a flowchart showing the operation procedure of the fourth embodiment.

Steps S61 and S62 are the same as steps S1 and S2 in FIG. Following step S62, by using the command vehicle speed V _L, V _R of the left and right wheels calculated at step S62, the travel turning radius R _C and the velocity V _C of the vehicle of the vehicle is calculated (step S63, S64).

Then, the centrifugal acceleration G is calculated using the traveling radius R _{C of the} vehicle and the velocity V _C (step S
65), the magnitude of the centrifugal acceleration G and the set value Gmax is discriminated (step S66). And G ≦ Gmax
If so (NO in step S66), the process proceeds to step S68, while if G> Gmax (Y in step S66).
ES), correction command vehicle speed V _L ', V _R' is calculated (step S67), the process proceeds to step S68.

The following steps S68 to S72 are the same as those in FIG.
The same as steps S6 to S10.

[0108] Thus, according to the fourth embodiment, as in centrifugal acceleration G of the vehicle is less than or equal to the specified value Gmax, command vehicle speed V _L of right and left wheels, V _R the correction command vehicle speed V _L ', V _R Since the correction is made to ', deterioration in riding comfort can be prevented even if the tilt angle of the joystick 11 is operated at the maximum speed and the vehicle travels while making a turn. Also, each command vehicle speed V _L, V _R
Is corrected so that the traveling turning radius does not change, so that the operation of the joystick 11 and the actual traveling of the electric wheelchair can be matched with each other, and thus the operability can be prevented from being deteriorated.

The third embodiment may be added to the first embodiment or the second embodiment.
That is, the command vehicle speed V _L of right and left wheels obtained in the third embodiment, the V _R, command vehicle speed V _L of right and left wheels in the first embodiment or the second embodiment may be used as V _R. In this case, the command vehicle speed calculation unit 72 shown in FIG. 1 or 6 may perform the weighted calculation of the horizontal component of the tilt angle of the joystick 11.

[0110]

As described above, according to the first aspect of the invention, the command wheels of the respective drive wheels instructed according to the operation amount of the first operation and the operation amount of the second operation of the operating means. Since the correction for reducing the absolute value of each command wheel speed is made according to the magnitude of the absolute value of the speed difference, the difference between the command wheel speed differences of the respective drive wheels instructed by the operation performed by the operation means is performed. When the absolute value is large, that is, when the vehicle's turning radius is small, each commanded wheel speed is corrected to a small value, which can reduce the centrifugal force generated in the vehicle. It is possible to prevent deterioration of comfort.

Further, according to the invention of claim 2, the command wheel speed of each drive wheel instructed according to the operation amount of the first operation and the operation amount of the second operation of the operating means is used to drive the vehicle. Since the centrifugal acceleration is calculated and the commanded wheel speed of each drive wheel is corrected so that this centrifugal acceleration matches a preset value, when the vehicle has a small turning radius due to the operation performed by the operation means. However, the centrifugal acceleration generated in the vehicle can be maintained below the set value, and the deterioration of the riding comfort of the vehicle can be reliably prevented.

According to the third aspect of the present invention, the commanded wheel speed of each drive wheel is indicated by reducing the weighting of the operation amount of the second operation compared to the operation amount of the first operation. Therefore, the absolute value of the difference between the command wheel speeds of the respective drive wheels is reduced compared to the operation amount performed by the operating means, and the traveling turning radius of the vehicle is not reduced by this, so that a large centrifugal force is generated in the vehicle. Can be prevented, and the reduction in riding comfort can be prevented more reliably.

Further, according to the invention of claim 4, the command wheel speed of each drive wheel is corrected so as not to change the traveling turning radius of the vehicle due to the operation performed by the operating means. It is possible to prevent the deterioration of the ride comfort of the vehicle while preventing the deterioration of the ride quality of the vehicle.

According to the fifth aspect of the invention, the commanded wheel speed of each drive wheel is instructed by reducing the weighting of the operation amount of the second operation as compared with the operation amount of the first operation of the operation means. As a result, the absolute value of the difference between the command wheel speeds of the drive wheels is reduced compared to the amount of operation performed by the operating means, and the traveling turning radius of the vehicle is not reduced by this, so a large centrifugal force is applied to the vehicle. It is possible to prevent the occurrence of the occurrence, and it is possible to prevent the ride comfort from being deteriorated even when the operation amount of the operation means is large.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control configuration of a first embodiment of an electric wheelchair to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a tilt direction and a tilt angle of a joystick 11.

FIG. 3 shows a joystick 11 as shown in FIG.
When the rotated operation on the right side of the left-right direction component (+) from the front of the front-rear direction component (+) at the maximum tilt angle, the left wheel speed V _L for the value X in the left-right direction component, right wheel speed V _R, left and right speed difference wheel (V _L -V _R) and the vehicle speed _{V C = (V L + V} R)
It is a figure which shows / 2.

FIG. 4 is a diagram showing an example of a function G ₁ .

FIG. 5 is a flowchart showing an operation procedure of the first embodiment.

FIG. 6 is a block diagram showing a control configuration of a second embodiment of an electric wheelchair to which the present invention is applied.

FIG. 7 is a diagram showing an example of a function G ₂ .

FIG. 8 is a flowchart showing an operation procedure of the second embodiment.

FIG. 9 is a block diagram showing a control configuration of a third embodiment of an electric wheelchair to which the present invention is applied.

FIG. 10 is a flowchart showing an operation procedure of the third embodiment.

FIG. 11 is a flowchart showing an operation procedure of the fourth embodiment.

FIG. 12 is a schematic diagram for explaining the speed and turning radius of the drive wheels when the vehicle is turning.

[Explanation of symbols]

1 Operation Panel 11 Joystick (Operating Means) 12 Main Switch 2 Power Supply Units 3L, 3R Motors (Left Driving Means, Right Driving Means) 31L, 31R Vehicle Speed Sensors 4L, 4R Relays (Left Driving Means, Right Driving Means) 5L, 5R Motors Control unit (left driving unit, right driving unit) 6 control board 7 CPU 71 joystick input unit 72 commanded vehicle speed calculation unit 73 vehicle speed calculation unit 74 commanded vehicle speed correction calculation unit (correction unit, acceleration calculation unit, comparison unit, radius calculation unit) 75 PWM Wave Calculator (Drive Control Means) 76 Left / Right Component Weighting Calculator (Operating Means) 8 Memory

Claims (5)

[Claims] 1. A vehicle having left driving means for rotationally driving a left driving wheel and right driving means for rotationally driving a right driving wheel, wherein the left and right driving wheels are rotationally driven in the same direction at the same wheel speed. A first operation for rotating the left and right driving wheels in opposite directions to each other at a predetermined wheel speed;
Of the command wheel speed of each of the driving wheels, and the command wheel speed of each of the driving wheels instructed. Correction means for correcting the absolute value of each of the command wheel speeds according to the magnitude of the absolute value of the difference, and the left driving means for rotationally driving each of the drive wheels with the corrected command wheel speeds. And a drive control means for controlling the right drive means, the vehicle speed control device. 2. A vehicle having left driving means for rotationally driving a left driving wheel and right driving means for rotationally driving a right driving wheel, wherein the left and right driving wheels are rotationally driven in the same direction at the same wheel speed. A first operation for rotating the left and right driving wheels in opposite directions to each other at a predetermined wheel speed;
The operation can be performed independently or at the same time, and the operating means for instructing the command wheel speed of each drive wheel according to the operation amount of each operation, and the command wheel speed of each instructed drive wheel are Acceleration calculating means for calculating the centrifugal acceleration of the vehicle by using the comparing means for comparing the calculated centrifugal acceleration with a preset value; and when the centrifugal acceleration is larger than the set value, the centrifugal acceleration Correction means for correcting the command wheel speeds of the respective drive wheels so as to match the set value, and the left driving means and the right driving means for rotationally driving the respective drive wheels with the corrected respective command wheel speeds. And a drive control means for controlling the vehicle speed control device. 3. The operating means reduces the weighting of the operation amount of the second operation as compared with the operation amount of the first operation to instruct each of the command wheel speeds. The vehicle speed control device according to claim 1 or 2. 4. The vehicle speed control device according to claim 1, wherein a radius calculation for calculating a traveling turning radius of the vehicle by using a command wheel speed of each drive wheel instructed by the operation means. A vehicle speed control device comprising: means for correcting the commanded wheel speed of each drive wheel so that the traveling turning radius does not change. 5. A vehicle having left driving means for rotationally driving a left driving wheel and right driving means for rotationally driving a right driving wheel, wherein the left and right driving wheels are rotationally driven in the same direction at the same wheel speed. A first operation for rotating the left and right driving wheels in opposite directions to each other at a predetermined wheel speed;
The operation can be performed independently or simultaneously, and the operation means for instructing the command wheel speed of each drive wheel according to the operation amount of each operation, and the command wheel speed of each drive wheel instructed Drive control means for controlling the left drive means and the right drive means for rotationally driving the respective drive wheels, wherein the operating means operates the second operation as compared with the operation amount of the first operation. A vehicle speed control device, wherein weighting of quantity is reduced to instruct a command wheel speed of each drive wheel.