JPH09149510A - Electric transporting vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an easy-to-operate electric transporting vehicle. SOLUTION: A variable resistor VR1 for steering control outputs a manual steering signal Hs corresponding to the horizontal movement of an operation lever. This manual steering signal Hs is converted into a manual steering signal Hs' by a manual steering signal generating circuit 30. A variable resistor VR2 for speed control outputs a manual speed signal Hv corresponding to the vertical movement of the operation lever. Also, a dead zone generating circuits 31, 32 output a '0' signal when each absolute value of the inputted manual steering signal Hs' and manual speed signal Hv is less than a fixed value and a '1' signal when it is greater than the fixed value. A switch 45 makes contacts 45a, 45b when the '1' signal is outputted from an OR-gate circuit 34 and breaks the contacts with the '0' signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle used for carrying a golf bag or the like on a golf course.

[0002]

2. Description of the Related Art Conventionally, in a golf course, an electric vehicle for carrying a golf bag or the like (so-called,
Golf carts) are used. FIG. 6 is a side view showing an external configuration of the electric transport vehicle. In this figure, 1 is a mounting table on which a golf bag or the like is mounted.
Reference numeral 2 denotes a driving wheel rotatably attached to the lower portion of the mounting table 1 via a shaft, which is rotationally driven by a motor. Reference numeral 3 is a follower wheel rotatably attached to the lower portion of the mounting table 1 via a shaft. Reference numeral 4 denotes a handle having one end 4a attached and fixed to the mounting table 1. This handle 4
Various switches necessary for operating the electric transport vehicle are attached to the grip portion 4b, and the operator drives the electric transport vehicle while gripping the grip portion 4b.

Here, FIG. 7 shows an electrical configuration of the above-described electric vehicle. In this figure, SW is a handle 4
The switch is attached to the grip portion 4b (see FIG. 6) and performs a forward / reverse switching operation, and is operated by the operator.

XF and XR are relays, and xF and xR are contacts of the relays XF and XR, respectively. A DC power supply 5 supplies power to each part of the device. Reference numeral 6 denotes an electric motor that rotationally drives the driving wheel 2 (see FIG. 6) via a shaft. Reference numeral 7 denotes a speed control variable resistor attached to the grip portion 4b of the handle 4, which is operated by an operator,
It is a variable resistor that controls the traveling speed. Reference numeral 8 is a controller that supplies the electric motor 6 with a drive voltage having a magnitude corresponding to the operation amount of the speed control variable resistor 7.

In the above structure, when the operator turns on the switch SW on the forward side, the relay XF is excited and the contact xF is turned on to the terminal p side. As a result, the electric motor 6 is supplied with a voltage according to the operation amount of the speed control variable resistor 7 from the controller 8, and the electric motor 6
Is driven forward. As a result, the driving wheel 2 is driven in the normal direction via the shaft, and the electric vehicle travels forward in the direction A shown in FIG. After that, when the operator walks while following the electric transport vehicle and adjusts the traveling speed of the electric transport vehicle,
The variable resistor 7 for speed control is operated.

Next, when the operator turns on the switch SW to the reverse side, the excitation of the relay XF is released and the contact xF is turned on to the terminal n side, then the relay XR is excited and the contact xR is turned to the terminal p. It is thrown into the side. As a result, a reverse voltage is supplied to the electric motor 6 from the controller 8 and the electric motor 6 is driven in reverse. As a result, the driving wheel 2 is reversely driven via the shaft, and the electric transport vehicle travels backward in the direction B shown in FIG.

[0007]

By the way, in the above-mentioned conventional electric transport vehicle, a slight movement of the handle 4 causes a change in the resistance value of the speed control variable resistor 7 to bring it into an operating state. There is a drawback that the operability is poor because it causes a malfunction. The present invention has been made under such a background, and an object of the present invention is to provide an electric transport vehicle having excellent operability.

[0008]

According to a first aspect of the present invention, there is provided a variable resistor for operation control, operation control means for performing operation control based on the output of the variable resistor, and the operation control means. A dead zone that outputs the first signal when the absolute value of the output voltage of the variable resistance and the traveling wheel that is drive-controlled is equal to or higher than a preset constant value, and outputs the second signal when the absolute value of the output voltage is equal to or lower than the constant value. It is characterized by comprising a generating means and an operation control means for bringing the operation control means into an operating state when the first signal is output from the dead zone generating means.

According to a second aspect of the invention, based on the outputs of the first variable resistor for speed control, the second variable resistor for steering control, and the first and second variable resistors. When the absolute value of the output voltage of the operation control means for performing the operation control by means of the operation control means, the traveling wheels controlled by the operation control means, and the first variable resistor is equal to or greater than a preset first constant value. , If the first signal is less than or equal to the first constant value, the second signal
The first dead zone generating means for outputting the signal of No. 2 and the absolute value of the output voltage of the second variable resistor is equal to or more than a preset second constant value, the first signal is changed to the second Second dead zone generating means for outputting a second signal when the value is equal to or less than a certain value, and the operation control means is operated when the first signal is output from the first or second dead zone generating means. It is characterized by comprising an operation control means.

According to a third aspect of the present invention, in the electric vehicle according to the second aspect, when the absolute value of the output of the second variable resistor is equal to or less than a constant value, the 0 level signal is kept constant. A steering signal generation circuit that outputs a voltage whose level sequentially changes according to the rotation angle of the slider of the second variable resistor when the value is equal to or more than the value is provided, and instead of the output of the second variable resistor, The output of the steering signal generation circuit is applied to the operation control means and the second dead zone generation means.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an external configuration of an electric vehicle (golf cart) according to an embodiment of the present invention, and FIG. 2 is a rear view. In these figures, reference numeral 9
Is a cart body, a play wheel 12 is attached to the lower surface of the front end of the cart, a V-shaped bag mounting table 10 is provided in the center, and a storage box 9a in which a electric motor and its control circuit are stored is provided in the rear. Is attached.

A joystick mechanism 18a having an operating lever 18b is attached to the back surface of the storage box 9a, and the left drive wheel is attached to the lower portion of the storage box 9a via a left shaft 16L and a right shaft 16R (see FIG. 2). 17L and right driving wheel 17R are attached respectively. Also,
At the center of the lower surface of the cart main body 9, there are provided a guide sensor 13 for detecting a guide line G laid on the ground (see FIG. 2) and a stop position sensor 14 for detecting a stop position mark previously installed at the cart stop position. An obstacle sensor 15 is installed at each front end of the cart body 9.

FIG. 3 is a block diagram showing the electrical construction of the control unit of the electric vehicle (golf cart) according to the above embodiment. In this figure, the steering control variable resistor VR1 is a variable resistor whose resistance value changes in conjunction with left and right operation of the operating lever 18b (see FIG. 2), and the speed control variable resistor VR2 is of the operating lever 18b. It is a variable resistor whose resistance value changes in association with up and down operations (see FIG. 1).

Reference numeral 30 denotes a manual steering signal generation circuit, which is input from the steering control variable resistor VR1 and has a characteristic shown in FIG. 4 (A).
Is converted by the conversion characteristic having the dead zone N shown in FIG. 4B and output as the manual steering signal Hs ′.

A dead zone generating circuit 31 outputs a "0" signal when the absolute value of the input manual steering signal Hs' is less than a certain value, and outputs a "1" signal when it is more than a certain value. Here, the constant value is set to almost 0 level, and as a result, the output of the dead zone generating circuit 31 is as shown in FIG.
As shown in (C), the signal is "0" in the dead zone N and "1" in the other areas. Reference numeral 32 is also a dead zone generating circuit having the same structure. However, in the case of the dead zone generating circuit 32, the above-mentioned constant value is the dead zone generating circuit 31.
It is set somewhat higher. As a result, a "0" signal is output from the dead zone generating circuit 32 when the output of the variable resistor VR2 is close to 0, and a "1" signal is output when the absolute value of the output exceeds a certain value.

Reference numeral 33 is an OR gate circuit. The dead band generating circuit 31 is provided at each input terminal of the OR gate circuit 33.
The 32 output signals are respectively input. 34 is an OR gate circuit, and at each input terminal of the OR gate circuit 34,
Output of OR gate circuit 33 and automatic driving mode signal S
a is input respectively. The automatic traveling mode signal Sa is a signal that gives a traveling start command in the later-described automatic traveling mode.

Reference numeral 35 denotes an automatic steering signal generation circuit for generating an automatic steering signal As which gives a steering command in the automatic traveling mode. The automatic steering signal generation circuit 35 converts the right shift amount DR or the left shift amount DL with respect to the guide line G, which is recognized from the output of the guide sensor 13 (see FIG. 2), with the conversion characteristic shown in FIG. Output as steering signal As. That is, the automatic steering signal generation circuit 35 outputs a positive automatic steering signal As proportional to the left shift amount DL and a negative automatic steering signal As proportional to the right shift amount DR. Is output.

In FIG. 3, reference numeral 36 is a resistor for outputting an automatic speed signal Av which gives a running speed command in the automatic running mode. Reference numeral 37 denotes a switch, which receives the manual steering signal Hs' output from the manual steering signal generation circuit 30 at the manual side terminal 37a and the automatic steering signal output from the automatic steering signal generation circuit 35 at the automatic side terminal 37b. As is input, and switching control is performed by a control device (not shown). 38 is PI
(Proportional-integral) control circuit that proportionally
Integral control and output.

Reference numeral 39 is a subtracter, which is a PI control circuit 52.
The output signal of the PI control circuit 38 is subtracted from the output signal of, and the result of the subtraction is output as a right electric motor speed command signal SR that gives a command of the rotation speed and the rotation direction of the right electric motor 49R described later. 40 is a PI control circuit.
Reference numeral 41 denotes a subtracter, which subtracts a rotation speed signal NR fed back from an encoder 50R described later from the output signal of the PI control circuit 40. 42 is a PI control circuit. Reference numeral 43 is a subtracter, which subtracts a current detection signal SIR fed back from a current detector 48R described later from the output signal of the PI control circuit 42.

Reference numeral 44 is a PI control circuit. Reference numeral 45 is a switch having contacts 45a and 45b, and when the "1" signal is output from the OR gate circuit 34, the contacts 45a and 45b.
It is opened when b is contacted and a "0" signal is output. Reference numeral 46 denotes a PWM (pulse width modulation) circuit, which applies a DC voltage supplied from a DC power source (not shown) to a contact 45.
It is converted into a chopper voltage VR having a polarity and a pulse width corresponding to the control signal input via a and output.

Reference numeral 47 is an amplifier circuit for amplifying the chopper voltage VR supplied from the PWM circuit 46, and supplies the amplified chopper voltage VR to the right electric motor 49R. The right electric motor 49R rotationally drives the right driving wheel 17R via the right shaft 16R shown in FIG. The current detector 48R detects the drive current IR supplied to the right electric motor 49R and feeds back the detection result to the subtractor 43 as a current detection signal SIR. Encoder 50R is a right electric motor 49R
Is detected and the detection result is fed back to the subtractor 41 as a rotation speed signal NR.

Reference numeral 51 is a switch, which is a manual side terminal 51a.
The manual speed signal Hv output from the variable resistor VR2 for speed control is input to, and the automatic speed signal Av output from the resistor 36 is input to the automatic side terminal 51b, and switching control is performed by a control device (not shown). 52 is a PI control circuit. Reference numeral 53 denotes an adder that adds the output signal of the PI control circuit 52 and the output signal of the PI control circuit 38 and outputs the addition result to the left electric motor 49L that gives a command of the rotational speed and the rotational direction of the left electric motor 49L described later. Motor speed command signal S
Output as L.

Reference numeral 54 is a PI control circuit. Reference numeral 55 denotes a subtracter, which subtracts a rotation speed signal NL fed back from an encoder 50L described later from the output signal of the PI control circuit 54. Reference numeral 56 is a PI control circuit. 5
A subtracter 7 subtracts a current detection signal SIL fed back from a current detector 48L described later from the output signal of the PI control circuit 56.

Reference numeral 58 is a PI control circuit. Reference numeral 59 is a PWM circuit having a function similar to that of the PWM circuit 46 described above, and outputs the chopper voltage VL. Reference numeral 60 denotes an amplifier circuit, which is a chopper voltage VL output from the PWM circuit 59.
Is amplified and supplied to the left electric motor 49L. The left electric motor 49L rotationally drives the left driving wheel 17L via the left shaft 16L shown in FIG. The current detector 48L detects the drive current IL supplied to the left electric motor 49L and feeds back the detection result to the subtractor 57 as a current detection signal SIL. The encoder 50L detects the rotation speed of the left electric motor 49L and feeds back the detection result to the subtractor 55 as a rotation speed signal NL.

Next, the operation of the electric vehicle according to the above embodiment will be described. This operation includes a manual traveling mode in which the operator drives and an automatic traveling mode in which the vehicle automatically travels while being guided by the guide line G (see FIG. 2). << Manual Travel Mode >> First, the manual travel mode will be described. In FIG. 1, first, when an operator turns on a power switch (not shown) and then a manual / automatic changeover switch (not shown) is switched to the manual side,
By the control device, the movable pieces 37c and 51c of the switching devices 37 and 51 shown in FIG. 3 are put into the manual side terminals 37a and 51a, respectively.

<Manual / Forward Operation> Subsequently, the operator tilts the operating lever 18b in the C direction shown in FIG. 1 with the operating lever 18b in the substantially central position in the left-right direction in order to cause the electric carrier to travel forward. In this case, the steering control variable resistor VR1 outputs a manual steering signal Hs of almost 0 level, and therefore the manual steering signal generation circuit 30 outputs a manual steering signal Hs' of 0 level, thereby generating a dead zone. A "0" signal is output from the circuit 31.

On the other hand, the manual speed signal Hv output from the speed control variable resistor VR2 takes a positive value and gradually increases from 0 according to the operation of the operation lever 18b. Here, when the level of the manual speed signal Hv is smaller than a fixed value, the dead zone generation circuit 32 outputs a "0" signal.
In this case, since the output of the OR gate circuit 33 becomes the "0" signal and the automatic traveling mode signal Sa is "0",
The OR gate circuit 34 outputs a "0" signal. As a result, the contacts 45a and 45b of the switch 45 are turned off,
The control signals are not supplied to the PWM circuits 46 and 59, and the motors 49R and 49L are not driven.

Next, when the level of the manual speed signal Hv output from the speed control variable resistor VR2 exceeds a certain value, the dead zone generating circuit 32 outputs a "1" signal. In this case, the output of the OR gate circuit 33 becomes the "1" signal, and the OR gate circuit 34 outputs the "1" signal. As a result, the contacts 45a and 45b of the switch 45 are turned on, and the control signals output from the PI control circuits 44 and 58 are supplied to the PWM circuits 46 and 59, respectively. The PWM circuits 46 and 59 form chopper voltages VR and VL based on the control signals, and supply them to the motors 49R and 49L via the amplifier circuits 47 and 60. As a result, the motor 49
R and 49L are driven, and the golf cart moves forward.

<Manual / Stopping Operation> Next, when the operator releases the operating lever 18b, the speed control variable resistor VR is released.
The level of the manual speed signal Hv output from 2 gradually decreases. When the level of the manual speed signal Hv becomes smaller than a certain value, the signal output from the dead zone generating circuit 32 changes from "1" to "0". As a result, the output of the OR gate circuit 33 becomes a "0" signal, and the OR gate circuit 3
"0" signal is output from 4 and contact 45 of switch 45
The a and 45b are turned off, the control signals are not supplied to the PWM circuits 46 and 59, the motors 49R and 49L are stopped, and the golf cart is stopped.

<Manual / reverse operation> Next, the operator tilts the operation lever 18b in the direction D shown in FIG. In this case, the steering control variable resistor VR1 outputs a manual steering signal Hs of almost 0 level, and a "0" signal is output from the dead zone generating circuit 31 in the same manner as the operation of <manual / forward operation>. Is output.

On the other hand, the manual speed signal Hv output from the speed control variable resistor VR2 takes a negative value and gradually increases from 0 according to the operation of the operation lever 18b. Here, when the absolute value of the manual speed signal Hv is smaller than a fixed value, the dead zone generation circuit 32 outputs a "0" signal.
As a result, the contacts 45a and 45b of the switch 45 are turned off, the control signal is not supplied to the PWM circuits 46 and 59, and the motors 49R and 49L are not driven.

Next, when the absolute value of the negative manual speed signal Hv output from the speed control variable resistor VR2 becomes larger than a certain value, the dead zone generating circuit 32 outputs a "1" signal. In this case, the output of the OR gate circuit 33 becomes the "1" signal, and the OR gate circuit 34 outputs the "1" signal. As a result, the contacts 45a and 45b of the switch 45 are turned on, and the control signals output from the PI control circuits 44 and 58 are supplied to the PWM circuits 46 and 59, respectively. PWM
The circuits 46 and 59 form negative chopper voltages VR and VL based on the control signals, and supply the negative chopper voltages VR and VL to the motors 49R and 49L through the amplifier circuits 47 and 60, respectively. As a result, the motors 49R and 49L are reversely driven, and the golf cart moves backward.

<Manual / Right-turning Operation> When the golf cart is turned right during the forward traveling, the operator operates the operation lever 18b at the substantially center position in the left-right direction and in the C direction (see FIG. 1). While tilted to, tilt further in direction A (see Figure 2). As a result, the manual steering signal Hs (see FIG. 4 (A)), which takes a positive value and gradually increases from 0 according to the operation of the operation lever 18b, is output from the steering control variable resistor VR1. Is output to. If the level of the manual steering signal Hs is smaller than a certain value,
Due to the conversion characteristic shown in (B), the manual steering signal Hs' of 0 level is output from the manual steering signal generation circuit 30.
Is output.

When the absolute value of the manual steering signal Hs becomes larger than a fixed value, the manual steering signal Hs from the manual steering generation circuit 30 gradually increases from 0 according to the operation of the operation lever 18b while taking a positive value. (See FIG. 4B) is output to the PI control circuit 38 via the dead zone generation circuit 31 and the switch 37. The positive manual steering signal Hs ′ input to the PI control circuit 38 is proportionally and integratedly controlled by the PI control circuit 38, and then is input to one input end of the subtractor 39 and the other input end of the adder 53, respectively. Is entered.

The subtractor 39 subtracts the positive output signal of the PI control circuit 38 from the positive output signal of the PI control circuit 52 and outputs the right electric motor speed command signal SR, while the adder 53 outputs the PI signal. The positive output signal of the control circuit 52 and the positive output signal of the PI control circuit 38 are added to output the left electric motor speed command signal SL. The left electric motor speed command signal SL is a signal that gives a speed command faster than the right electric motor speed command signal SR. Therefore, the left electric motor 49L
Is driven forward at a speed faster than the right electric motor 49R, so the golf cart turns right.

<Manual / Left Turn Operation> When the golf cart is turned left while the vehicle is traveling forward as described above, the operator operates the operation lever 18b at the substantially center position in the left-right direction and in the C direction (see FIG. 1). B further down
Direction (see Figure 2). As a result, the manual steering signal Hs (see FIG. 4A) from the steering control variable resistor VR1 gradually increases from 0 according to the operation of the operation lever 18b while taking a negative value. Is output to. Below, <Manual /
When the absolute value of the manual steering signal Hs becomes larger than a constant value by the same operation as the right turn operation>, the manual steering signal Hs gradually increases from 0 according to the operation of the operation lever 18b while taking a negative value from the manual steering signal generation circuit 30. The steering signal Hs ′ (see FIG. 4B) is output to the PI control circuit 38 via the dead zone generation circuit 31 and the switch 37.

The subtractor 39 subtracts the negative output signal of the PI control circuit 38 from the positive output signal of the PI control circuit 52 to output the right electric motor speed command signal SR, while the adder 53 outputs the PI signal. The positive output signal of the control circuit 52 and the negative output signal of the PI control circuit 38 are added to output the left electric motor speed command signal SL. Thus, the right electric motor speed command signal SR is a signal that gives a speed command faster than the left electric motor speed command signal SL. Therefore, the right electric motor 49R is driven to rotate normally at a faster speed than the left electric motor 49L, and the golf cart turns left.

<< Automatic Travel Mode >><Automatic / Forward Operation> Next, the operation in the automatic travel mode in which the vehicle automatically travels while guiding the guide line G shown in FIG. 2 will be described. First, the operator places the electric transport vehicle on the guide line G and then turns on a manual / automatic changeover switch (not shown) to the automatic side. As a result, the control device outputs the automatic traveling mode signal Sa of "1" to the input end of the OR gate circuit 34 shown in FIG. As a result, the "1" signal is output from the OR gate circuit 34, and the switch 4
5 is driven, and the contacts 45a and 45b are turned on.
At the same time, the control device causes the switching devices 37, 51 to
Movable pieces 37c and 51c of the automatic side terminals 37b and 51c, respectively.
b, respectively.

As a result, the automatic speed signal Av output from the resistor 36 is transmitted via the switch 51 to the PI control circuit 5
2 is input. Thereafter, in the same manner as the <manual / forward movement operation>, the right electric motor 49R and the left electric motor 49L are normally driven at the same rotation speed, and the golf cart moves forward.

<Automatic / Right Shift Correction Operation> Then, assuming that the guide sensor 13 shifts to the right by the right shift amount DR with respect to the guide line G, the automatic steering signal generation circuit 35.
Generates a negative automatic steering signal As according to the right shift amount DR using the conversion characteristic shown in FIG. 5, and outputs it to the PI control circuit 38 via the switch 37. Hereinafter, in the same manner as the operation described in <manual / left turn operation>, the right electric motor 49R is driven to rotate in the normal direction at a higher rotation speed than the left electric motor 49L, so that the electric transport vehicle moves relative to the guide line G. To the left while correcting the shift to the right.

The level of the negative automatic steering signal As output from the automatic steering signal generation circuit 35 gradually decreases (see FIG. 5) as the right shift amount DR gradually decreases. When the right deviation amount DR becomes 0, the rotational speed difference between the right electric motor 49R and the left electric motor 49L becomes 0, and the golf cart travels forward.

<Automatic / Left Shift Correction Operation> If the guide sensor 13 is shifted to the left by the left shift amount DL with respect to the guide line G, the automatic steering signal generation circuit 35
Using the conversion characteristic shown in FIG. 5, a positive automatic steering signal As corresponding to the left shift amount DL is generated, and the switch 37
To the PI control circuit 38 via. Thereafter, the left electric motor 49L is driven to rotate forward at a faster rotation speed than the right electric motor 49R by the operation opposite to the <automatic / right shift correction operation> described above, so that the electric transport vehicle is guided to the guide line G. On the other hand, drive to the right while correcting the left shift.

Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present invention. Even so, it is included in the present invention. For example, in the electric transport vehicle according to the above-described embodiment, the example in which the electric motor is used as the drive source has been described, but a small engine may be used instead.

[0044]

EFFECTS OF THE INVENTION According to the present invention, since the dead zone generating means is provided, erroneous operation is eliminated, so that the operability is improved.

[Brief description of the drawings]

FIG. 1 is a side view showing an external configuration of an electric transport vehicle according to an embodiment of the present invention.

FIG. 2 is a rear view showing the external configuration of the electric transport vehicle according to the same embodiment.

FIG. 3 is a block diagram showing an electrical configuration of a control unit of the electric vehicle according to the same embodiment.

4 is a diagram showing characteristics of a manual speed signal Hv, a manual steering signal Hs, a manual steering signal generation circuit 30, and dead zone generation circuits 31 and 32 shown in FIG.

5 is an automatic steering signal generation circuit 35 shown in FIG.
It is a figure which shows the conversion characteristic of.

FIG. 6 is a side view showing an external configuration of a conventional electric vehicle.

FIG. 7 is a circuit diagram showing an electrical configuration of a conventional electric vehicle.

[Explanation of symbols]

 17R Right driving wheel 17L Left driving wheel 18a Joystick mechanism 18b Operating lever 30 Manual steering signal generation circuit 31, 32 Dead zone generation circuit 33, 34 OR gate circuit 39 Subtractor 49R Right electric motor 49L Left electric motor 53 Adder Hs, Hs' Manual steering signal Hv Manual speed signal VR1 Steering control variable resistor VR2 Speed control variable resistor SR Right electric motor speed command signal SL Left electric motor speed command signal

Claims (3)

[Claims] 1. A variable resistor for operation control, operation control means for performing operation control based on the output of the variable resistor, traveling wheels drive-controlled by the operation control means, and Dead band generating means for outputting a first signal when the absolute value of the output voltage is equal to or greater than a preset constant value and a second signal when the absolute value is equal to or less than the preset value; and a first signal from the dead zone generating means. And an operation control means for bringing the operation control means into an operating state when is output. 2. A first variable resistor for speed control, a second variable resistor for steering control, and operation control for performing operation control based on the outputs of the first and second variable resistors. Means, a running wheel driven and controlled by the operation control means, and a first signal when the absolute value of the output voltage of the first variable resistor is equal to or greater than a preset first constant value, A first dead zone generating means for outputting a second signal when the value is equal to or less than a first constant value, and an absolute value of an output voltage of the second variable resistor is equal to or greater than a preset second constant value A second dead zone generating means for outputting a first signal and a second signal when the second signal is equal to or less than a second constant value; and the first signal is output from the first or second dead zone generating means. An operation control means for bringing the operation control means into an operating state when That motor-driven cart. 3. A signal of 0 level when the absolute value of the output of the second variable resistor is below a certain value, and a rotation angle of the slider of the second variable resistor when above a certain value. A steering signal generation circuit that outputs a voltage whose level sequentially changes according to the above is provided, and instead of the output of the second variable resistor, the output of the steering signal generation circuit is used as the operation control means and the second dead zone. The electric vehicle according to claim 2, wherein the electric vehicle is applied to the generating means.