JPH08241124A - Electric vehicle controller - Google Patents

Abstract

PURPOSE: To prevent a collision against an obstacle by providing an obstacle sensor, and controlling the vehicle down to a speed where the vehicle can stop by load weight in consideration of inertia force when the distance between the obstacle and vehicle decreases to a certain distance and stopping the motor a certain-time travel later. CONSTITUTION: The obstacle sensor 9 detects the distance to the obstacle in the travel direction of the carrier and a piezoelectric sensor 10 detects the load weight, and they are always outputted as voltage signals to a main control circuit 11. The main control circuit 11 controls the vehicle speed according to values obtained by mapping vehicle speeds by the load weight so that the carrier can stop in consideration of the inertial force when the distance between the vehicle and obstacle reaches the certain distance, and stops the motor 8 the certain-distance travel later. A duty generating circuit 12 outputs a duty signal based on the output voltage of the main control circuit 11 and a transistor 13 turns on and off repeatedly in association with the duty signal outputted by the duty generating circuit 12 to bring the motor 8 under chopper control, thereby varying the vehicle speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric carrier, and more particularly to an electric carrier suitable for carrying heavy objects.

[0002]

2. Description of the Related Art As a conventional technique, there is one that detects an object in the traveling direction and limits the maximum vehicle speed to a predetermined value, as disclosed in Japanese Patent Laid-Open No. 3-86005. However, this merely lowers the vehicle speed depending on the distance to the obstacle, and there is a problem that the vehicle collides with the obstacle if the vehicle continues to run.

[0003]

SUMMARY OF THE INVENTION According to the present invention, when an obstacle in the traveling direction of an electric carrier is detected, the vehicle is always stopped at a position in front of the obstacle to prevent a collision with the obstacle. With the goal.

[0004]

In order to achieve the above object, the present invention provides an obstacle for detecting a distance between a piezoelectric sensor for detecting a load weight on a bed portion of an electric carrier and an obstacle at a front part of the carrier. An object sensor is provided, and when the distance between the obstacle and the vehicle approaches a certain distance, the vehicle speed is regulated to a stopable speed for each loaded weight in consideration of inertial force, and the motor is stopped after traveling for a certain time.

[0005]

In the electric transport vehicle according to the present invention, the vehicle is always stopped before the obstacle so that the collision with the obstacle can be prevented.

[0006]

1 is a perspective view of an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a luggage carrier portion 4.

In FIG. 1, 1 is a variable resistance type speed setting volume for controlling the vehicle speed of an electric carrier, 2 is a push handle, 3 is a battery which is a power source, 4 is a loading platform for loading luggage, and 5 is for supporting the loading platform. Traveling wheels, 6 drive wheels for traveling the electric carriage, 7 a speed reducer for transmitting the power of the motor to the drive wheels, 8 a motor as a power source for causing the electric carriage to travel, 9 forward An obstacle sensor which detects the distance to an obstacle is shown.

In FIG. 2, reference numeral 10 denotes a mat type piezoelectric sensor for detecting the weight of a load placed on the luggage carrier, which is provided on the lower surface of the luggage carrier 4.

FIG. 3 shows a control circuit configuration of the present invention. The battery is a main control circuit 11 and a duty generating circuit 1.
2 is connected to the + side of the motor 8, the obstacle sensor 9 and the piezoelectric sensor 10 are in parallel with the main control circuit 11, and the speed setting volume 1 for controlling the vehicle speed is in the middle of the main control circuit 11 and the duty generation circuit 12. The transistor 13 is connected to the negative side of the motor 8.

Next, the operation of the control circuit shown in FIG. 4 will be described. First, the obstacle sensor 9 detects the distance to an obstacle in the traveling direction of the transport vehicle, the piezoelectric sensor 10 detects the load weight, and the voltage signals are constantly output to the main control circuit 11. In the main control circuit 11, as shown in the vehicle travel diagram of FIG. 3, when the vehicle and the obstacle 15 are within a certain distance, the vehicle speed is set in advance according to a value that maps the vehicle speed so that the vehicle can be stopped including the inertial force for each loaded weight. Restrict and stop the motor after traveling a certain distance. However, when the vehicle and the obstacle 15 are separated by a certain distance or more, the vehicle speed regulation is released. The signal subjected to control processing by the main control circuit 11 is output to the duty generation circuit 12 as a voltage signal. FIG. 5 shows the relationship between the obstacle distance, the loaded weight, and the maximum vehicle speed, which are mapped in advance by the main control circuit 11.

The duty generating circuit 12 is a main control circuit 1.
Duty output is performed based on the output voltage of 1. The output at this time has the output voltage of the main control circuit 11 as the maximum duty, and within this range, the resistance value of the speed setting potentiometer 1
It changes depending on the partial pressure value with the resistor 14. FIG. 6 shows the relationship between the input voltage and the output duty of the duty generating circuit 12. Further, the transistor 13 is repeatedly turned on and off in synchronization with the duty signal output from the duty generation circuit 12, and controls the motor 8 by chopper to change the vehicle speed.

As described above, when the vehicle and the obstacle 15 are within a predetermined distance by the signal from the obstacle sensor 9, the vehicle speed is regulated to a stopable vehicle speed according to the loaded weight detected by the piezoelectric sensor 10. By stopping the motor 8, it is possible to prevent the vehicle from colliding with the obstacle 15.

[0013]

According to the present invention, when the distance between the vehicle and the obstacle is within a certain distance, the motor is stopped after the vehicle travels at a vehicle speed that can be stopped for each load including the inertial force, so that collision with the obstacle is prevented. You can do it.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of an electric carrier according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the cargo bed portion shown in FIG.

FIG. 3 is a vehicle travel explanatory diagram showing control contents of a main control circuit.

FIG. 4 is a control circuit diagram of the present invention.

FIG. 5 is a characteristic diagram showing a relationship between an obstacle distance, a loaded weight and a vehicle speed.

FIG. 6 is a characteristic diagram showing a relationship between an input voltage and an output duty of the duty generation circuit 12.

[Explanation of Codes] 1 ... Speed setting volume, 2 ... Handwheel, 3 ... Battery, 4 ... Loading platform, 5 ... Running wheel, 6 ... Drive wheel, 7 ... Reducer, 8 ... Motor, 9 ... Obstacle sensor, 10 ... Piezoelectric sensor, 11 ... Main control circuit, 12 ... Duty generation circuit, 1
3 ... Transistor, 14 ... Voltage dividing resistor, 15 ... Obstacle.

Front Page Continuation (72) Inventor Toshikatsu Ito No. 3085 Higashiishikawa Nishikonai, Hitachinaka City, Ibaraki 5 Hitachi Car Electronics Co., Ltd.

Claims (1)

[Claims] 1. A transport vehicle for loading and transporting luggage, a motor for driving and propelling the transport vehicle, a speed reducer for amplifying the propulsive force of the motor, and a battery for operating the motor. An electric transport vehicle including a controller for controlling the number of rotations of the motor, an obstacle sensor for detecting an obstacle in a detection area in the traveling direction, and a weight detection sensor for detecting a load weight of a bed portion. A means for reading a signal from the obstacle sensor and a signal from the weight detection sensor to select a vehicle speed that is mapped in advance, a means for detecting an obstacle distance from the obstacle sensor, and a load weight detected by a piezoelectric sensor A control device for an electric transport vehicle, characterized in that the vehicle speed is set to a predetermined value in accordance with a signal from the obstacle sensor.