KR100918202B1 - Rotation-driving control apparatus and method in a forklift truck - Google Patents

Abstract

The present invention relates to an apparatus and method for controlling the rotation of a forklift for automatically controlling the traveling speed by measuring the lateral acceleration when the forklift rotates, and according to the present invention, an acceleration sensor for measuring the lateral acceleration of the forklift; Memory means for previously storing respective reference rotor current values and reference field current values corresponding to a plurality of lateral acceleration values, respectively; The rotor current and the field current measured from the current measuring means are monitored, and if the lateral acceleration value measured from the acceleration sensor is provided, the reference rotor current value and the reference field current value corresponding to the lateral acceleration value are detected from the memory means, and the forklift truck Provided is a rotation driving control apparatus for a forklift including a CPU for controlling so that the rotor current and the field current applied to the drive motor of the reference rotor current and the reference field current. According to the present invention, it is possible to prevent safety accidents such as overturning of the vehicle and at the same time it is possible to control the rotational driving using only the acceleration sensor compared to the conventional rotational driving control apparatus and method, thereby reducing the manufacturing cost There is. In addition, when the lateral acceleration is less than the reference value it is possible to improve the work efficiency by enabling normal rotational running without deceleration of the running speed.

Description

ROTATION-DRIVING CONTROL APPARATUS AND METHOD IN A FORKLIFT TRUCK}

1 is a view showing the configuration of a rotary driving control device according to a preferred embodiment of the present invention.

FIG. 2 is a diagram illustrating a detailed configuration of the amplifier shown in FIG. 1.

3 is a flowchart showing an overall process of the rotational driving control method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: acceleration sensor 120: amplifier

130: AD converter 140: field current measuring unit

150: rotor current measuring unit 160: accelerator pedal detection unit

170: memory unit 180: CPU

The present invention relates to a rotation driving control apparatus and method of a forklift, and more particularly to a rotation driving control apparatus and method of the forklift to automatically control the traveling speed when the left / right turns in the forklift to enable the safe driving of the vehicle will be.

As is well known, forklifts are classified into engine-based forklifts using fuel and electric forklifts using electric power according to their power sources. Here, the electric forklift is operated by electricity supplied from a battery, and is mainly used in an indoor working environment because there is no exhaust gas and a low noise.

On the other hand, in such a forklift, the driving speed of the vehicle during the rotational driving according to the steering of the driver is closely related to the safety driving. In other words, if the driving speed is too fast during the rotation driving, the risk of an accident such as the vehicle overturning increases. Therefore, in order to prevent this, the conventional general forklift has a built-in function of automatically controlling the traveling speed when the vehicle runs.

In this regard, in the related art, in general, the steering speed and the input of the accelerator pedal are measured and the input speed of the accelerator pedal is decreased by a predetermined ratio in response to the measured steering angle so that the driving speed of the forklift driving is automatically reduced. Was used.

However, the conventional rotation control method is a method of simply controlling the speed of the vehicle according to the steering angle regardless of the lateral acceleration considering the actual driving speed and the steering angle. Therefore, in order to control the safe driving of the forklift, a control method considering the traveling speed and the rotation angle at the same time when the forklift is driven is required.

In this regard, Korean Patent Laid-Open Publication No. 1999-62668 "Industrial Vehicle Axle Fluctuation Control Device and Method", Korean Patent Laid-Open Publication No. 1998-080579 "Industrial Vehicle Axle Controller", and Patent Publication 1999-0037475 "Industrial Vehicle Axle Tilt Control Method and Apparatus ", Patent Publication No. 1999-0062619" Tilt cylinder control device and method of an industrial vehicle ", Patent Publication No. 1999-0036657" A pivoting control device of the axle of an industrial vehicle "to solve the problem of the conventional rotation control method It suggests ways to do it. That is, in each of the above-mentioned prior patents, the driving state of the vehicle is determined according to the height, the traveling speed, the swinging degree, the swinging angle, and the like of the fork mounted on the vehicle, so that more stable rotational driving is possible.

However, in each of these prior patents, a plurality of sensors such as a height sensor, a vehicle speed sensor, a swing angle sensor, a pressure sensor, and a yaw rate sensor for measuring the height of the fork are additionally installed, and sensing received from each of the sensors According to the value, a locking mechanism for stabilizing the vehicle body must be additionally installed, which causes a problem of an increase in manufacturing cost.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, by measuring the lateral acceleration closest to the safe driving of the actual vehicle when the forklift rotates to automatically control the running speed and at the same time the conventional driving control device The purpose of the present invention is to provide an apparatus and method for controlling the rotation of the forklift, which is more simplified than the general means.

According to a preferred embodiment of the present invention for achieving the above object,

An apparatus for controlling rotation of a forklift, comprising: an acceleration sensor for measuring a lateral acceleration of the forklift; Current measuring means for measuring a field current and a rotor current applied to the drive motor of the forklift; Memory means for storing respective reference rotor current values and reference field current values corresponding to a plurality of lateral acceleration values, respectively; The rotor current and the field current measured from the current measuring means are monitored, and if the lateral acceleration value measured from the acceleration sensor is provided, the reference rotor current value and the reference field current value corresponding to the lateral acceleration value from the memory means are provided. And a CPU for controlling the rotor current applied to the driving motor of the forklift to be equal to or less than the reference rotor current value, and controlling the field current applied to the forklift driving motor to be equal to or greater than the reference field current. Provided is a rotation driving control apparatus for a forklift that is configured.

According to another preferred embodiment of the present invention for achieving the above object,

A forklift driving control method, comprising: a first step of setting reference rotor current values and reference field current values corresponding to a plurality of lateral acceleration values and storing them in a memory means; A second step of measuring lateral acceleration according to rotation of the forklift using an acceleration sensor; A third step of detecting from the memory means a reference rotor current value and a reference field current value corresponding to the measured lateral acceleration value; And rotating the forklift by controlling a rotor current and a field current applied to the driving motor of the forklift based on the detected reference rotor current value and the reference field current value. Provides a driving control method.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings.                     

First, as is well known, the lateral acceleration of the vehicle being driven is increased in correspondence with the running speed and the rotation angle of the vehicle. That is, when the vehicle is rotating, the centrifugal force of the vehicle body is generated in the direction perpendicular to the driving direction and in the opposite direction of the rotation, thereby reducing the stability of the vehicle. In this case, the lateral acceleration generated in response to the centrifugal force is proportional to the traveling speed of the vehicle. As the lateral acceleration increases, the risk of vehicle overturning increases. Therefore, the present invention measures the lateral acceleration when the forklift rotates, and automatically controls the running speed of the vehicle accordingly. For this purpose, a rotation driving control device including an acceleration sensor capable of measuring the lateral acceleration is mounted inside the forklift. do.

1 is a block diagram showing the overall configuration of the rotational driving control apparatus according to the present invention, the acceleration sensor 110, the amplifier 120, the AD converter 130, the field current measuring unit 140, the rotor The current measuring unit 150, the accelerator pedal detecting unit 160, the memory unit 170, and the CPU 180 are illustrated.

Referring to Figure 1 in detail with respect to the function of each of the constituent means, the acceleration sensor 110 means a means for measuring the lateral acceleration when the forklift rotates in accordance with the present invention, the detection signal corresponding to the measured lateral acceleration It is transmitted to the amplifier 120 to be described later. The acceleration sensor having such a function can be implemented using the most widely used piezoelectric acceleration sensor, and it is preferable to be mounted on the rear or front part of the vehicle that can detect the lateral acceleration most sensitively when the vehicle rotates.

The amplifier 120 amplifies and outputs the lateral acceleration detection signal provided from the acceleration sensor 110 to a predetermined level, and the AD converter 130 converts the amplified signal into a digital signal. The amplification unit 120 has an internal circuit configuration different according to the type of the acceleration sensor 110 described above. In general, piezoelectric acceleration sensors, which are not built-in amplifiers, are charged to minimize the influence of the line capacitance of the cable. Use an amplifier.

FIG. 2 is a diagram illustrating a detailed configuration of the amplifier 120, assuming that the aforementioned acceleration sensor 110 is a piezoelectric acceleration sensor, and shows a charge amplifier circuit corresponding thereto. Referring to FIG. 2, first, the charge amplifier is configured by using the OP-AMP. When the charge signal is input, the output voltage of the amplifier is fed back to the input circuit through the feedback capacitor C1, and as a result, a potential difference occurs at both ends of the capacitor. And, each of the resistance element VR2, R ₃ is, and determines the amplification factor (A), the amplification factor (A) in this case is a _{1+ v · (VR 2 / R} 3).

On the other hand, even if the same acceleration sensor is used, the magnitude of the lateral acceleration (G) generated in the vehicle may be different according to the type of the vehicle. By adjusting the ratio, it can be applied to all vehicles without changing the circuit. That is, by adjusting the variable resistance VR2 in Figure 2 it is possible to set the appropriate amplification rate for the lateral acceleration for the vehicle to which the rotational driving control apparatus according to the present invention is applied.

Subsequently, the field current measuring unit 140 and the rotor current measuring unit 150 shown in FIG. 1 are applied to the left and right traveling motors 12 and 13 as shown in FIG. It is a means for measuring the current, the accelerator pedal detecting unit 160 detects the operation degree of the accelerator pedal according to the driver's operation to generate a detection signal accordingly. The memory unit 170 pre-stores each field current value and the rotor current value corresponding to the plurality of lateral acceleration values.

The CPU 180 is a means typically provided in the forklift to control the operation of various electronic components provided in the forklift. The CPU 180 further includes a function for performing rotation control according to the present invention. That is, on the basis of the current values measured by each of the current measuring units 140 and 150, the field current value and the rotor current value applied to the current driving motor are recognized, and then the digital form is converted through the AD converter 130. A control signal for controlling the field current and the rotor current is generated based on the lateral acceleration provided by. In addition, the generated control signal is transmitted to the motor driving circuit (not shown) to reduce the rotation speed of the motor.

As a result, in the rotational driving control apparatus of the present invention, the speed of the vehicle is reduced by controlling the rotor current and the field current applied to the driving motor in response to the lateral acceleration of the forklift measured by the acceleration sensor 110.

On the other hand, in the actual application by mounting the rotational driving control apparatus of the present invention as described above, it is preferable to set a predetermined threshold value for the magnitude of the lateral acceleration for controlling the running speed. In other words, when the vehicle is traveling at low speed or the steering angle is not large, the risk of overturning is low. Therefore, it is not only meaningful to slow down the running speed of the vehicle but also reduce work efficiency. Therefore, the lateral acceleration value (threshold value) for starting the current control for decelerating the traveling speed is set in advance, and the current of the drive motor is controlled only when the lateral acceleration measured by the acceleration sensor 110 is equal to or greater than this threshold value. It is desirable to slow down the running speed of the vehicle.

3 is a flowchart illustrating an overall process of the rotation driving control method according to a preferred embodiment of the present invention. Hereinafter, each process will be described in detail with reference to the accompanying drawings.

First, in a state in which the field current value and the rotor current value corresponding to the respective lateral acceleration magnitudes are set in the memory unit 170, the acceleration sensor 110 continuously measures the lateral acceleration of the vehicle and detects the detected signal accordingly. It outputs (step S301). The sensing signal is amplified into a signal having a predetermined level through the amplifier 120 and converted into a digital signal through the AD converter 130.

Meanwhile, the CPU 180 continuously monitors the field current and the rotor current of the driving motor measured by the field current measuring unit 140 and the rotor current measuring unit 150 while the vehicle is running. In addition, the digital acceleration provided through the AD converter 130 described above is received and compared with a predetermined horizontal acceleration threshold (step S303).

If it is determined that the lateral acceleration of the forklift measured by the acceleration sensor 110 and provided through the amplifying unit 120 and the AD converter 130 is greater than or equal to a preset threshold (step S305), the CPU 180 stores the memory unit. A reference 170 is read to detect a reference rotor current value and a reference field current value corresponding to the currently measured lateral acceleration (step S307). Then, a control signal corresponding thereto is generated based on the detected reference rotor current value and the reference field current value to control the rotor current and the field current applied to the driving motor (step S309). That is, the rotor current applied to the drive motor is controlled so as not to exceed the detected reference rotor current, and the field current applied to the drive motor is controlled so as not to be less than the reference field current value. It decelerates (step S311).

On the other hand, unlike the comparison result in the above-described step (S303), if it is determined that the lateral acceleration of the forklift measured by the acceleration sensor 110 is less than the predetermined threshold value, the CPU 180 is applied to the rotor current to the drive motor And normal rotational running in the current state without controlling the field current (step S313). That is, the vehicle is driven at a speed corresponding to the accelerator pedal input value input through the accelerator pedal sensor 160.

As a result, the rotational driving control apparatus according to the present invention measures the lateral acceleration of the vehicle when the forklift rotates, and controls the current applied to the driving motor only when the measured lateral acceleration becomes equal to or more than a preset reference value, thereby driving the vehicle. Will automatically decelerate.

As described above, according to the present invention, it is possible to prevent safety accidents such as overturning of the vehicle by automatically measuring the lateral acceleration closest to the safety of the vehicle when the forklift is rotated and automatically controlling the traveling speed of the vehicle. In particular, compared to the conventional rotational driving control apparatus and method, it is possible to control the rotational driving using only the acceleration sensor, thereby reducing the manufacturing cost, and when the measured lateral acceleration is less than the reference value, without deceleration of the traveling speed. By enabling normal rotational driving, there is an effect of improving the work efficiency.

Claims (3)

In the device for controlling the rotational running of the forklift, An acceleration sensor for measuring lateral acceleration of the forklift; Current measuring means for measuring a field current and a rotor current applied to the driving motor of the forklift; Memory means for storing respective reference rotor current values and reference field current values corresponding to a plurality of lateral acceleration values, respectively; The rotor current and the field current measured from the current measuring means are monitored, and if the lateral acceleration value measured from the acceleration sensor is provided, the reference rotor current value and the reference field current value corresponding to the lateral acceleration value from the memory means are provided. And a CPU for controlling the rotor current applied to the driving motor of the forklift to be equal to or less than the reference rotor current value, and controlling the field current applied to the forklift driving motor to be equal to or greater than the reference field current. Rotation driving control device of the forklift configured. The method of claim 1, The CPU, The threshold value for the lateral acceleration is set in advance and stored, and when the measured lateral acceleration value exceeds the threshold value, the rotor current and the field current applied to the driving motor are controlled. Rotational run control device. In the forklift rotation control method, A first step of setting a reference rotor current value and a reference field current value corresponding to a plurality of lateral acceleration values and storing them in the memory means; A second step of measuring lateral acceleration according to rotation of the forklift using an acceleration sensor; A third step of detecting from the memory means a reference rotor current value and a reference field current value corresponding to the measured lateral acceleration value; And rotating the forklift by controlling a rotor current and a field current applied to the driving motor of the forklift based on the detected reference rotor current value and the reference field current value. Driving control method.

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