JP4088765B2 - Obstacle detection device for self-propelled transport vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an obstacle detection device for a self-propelled transport vehicle using an ultrasonic detection type obstacle detection sensor.
[0002]
[Prior art]
The self-propelled vehicle is provided with an ultrasonic detection type obstacle detection sensor, and the speed of the self-propelled vehicle is controlled based on the obstacle detection signal by the sensor, for example, two distances as the obstacle detection distance of the sensor. Based on the obstacle detection signal when an obstacle enters the long distance range, the self-propelled transport vehicle is decelerated to a low speed and based on the obstacle detection signal when the obstacle enters the short distance range There is known an obstacle detection device that stops and controls a self-propelled transport vehicle.
[0003]
[Problems to be solved by the invention]
This kind of self-propelled transport vehicle is rarely used in an environment where the ambient temperature is kept constant with an air conditioner, and is used in an environment where the ambient temperature changes greatly between summer and winter, such as in a factory. It is normal to be done. On the other hand, it is known that the sensitivity of ultrasonic detection type obstacle detection sensors used for obstacle detection decreases when the ambient temperature rises. Therefore, control corresponding to this change in ambient temperature is adopted. For example, when the sensitivity is adjusted in summer when the ambient temperature is high, the conventional obstacle detection device that has not been used detects and stops equipment in the vicinity of the traveling route of the self-propelled transport vehicle during the winter when the ambient temperature decreases. If the sensitivity is adjusted in winter when the ambient temperature is low, the sensor will not work for obstacles in the distance range that should be detected in the summer when the ambient temperature is high, such as an operator, causing a collision accident. There is a risk of leading to In order to avoid such a situation, there was a problem that the sensitivity of the sensor had to be adjusted during summer and winter.
[0004]
[Means for Solving the Problems]
An object of the present invention is to provide an obstacle detection device for a self-propelled transport vehicle capable of solving the above-described conventional problems, and the obstacle of the self-propelled transport vehicle according to claim 1. detection device, indicating depicted at embodiments discussed later, the self-propelled truck 1 provided an obstacle detecting sensor 8 for ultrasound detection formula, based on the obstacle detection signal of the sensor 8 An obstacle detection device that performs deceleration stop control of the self-propelled transport vehicle 1, and turns on / off reception monitoring for the obstacle detection sensor 8 at a constant period to detect an obstacle detection signal when the obstacle is detected. The self-propelled vehicle 1 is decelerated or stopped based on the sensor control means 9 for intermittently outputting the PL / PS , the temperature sensor 6, and the detected temperature T of the temperature sensor 6 and the obstacle detection signal PL / PS. Speed control signal C1 / C2 for The obstacle detection control means 10 includes an obstacle detection signal PL intermittently from the sensor control means 9 when the detected temperature T of the temperature sensor 6 is lower than a set temperature. When / PS is output, the speed control signal C1 / C2 is output when the number of outputs of the obstacle detection signal PL / PS reaches the set number of times, and the detected temperature of the temperature sensor 6 is equal to or higher than the set temperature. When the obstacle detection signal PL / PS is output intermittently from the sensor control means 9 at the time, the output number of the obstacle detection signal PL / PS reaches a set number less than the set number. The speed control signal C1 / C2 is output .
[0005]
In carrying out the present invention having the above-described configuration, specifically, as described in claim 2, the obstacle detection control means 10 performs the sensor control when the detected temperature of the temperature sensor 6 is equal to or higher than a set temperature. When the obstacle detection signal PL / PS is output intermittently from the means 9, the speed control signal C1 / C2 is output when the first obstacle detection signal PL / PS is output, and the detected temperature of the temperature sensor 6 is detected. When the obstacle detection signal PL / PS is output intermittently from the sensor control means 9 when the temperature is lower than the set temperature, the speed control signal C1 / C2 is output when the obstacle detection signal PL / PS is output for the second time. Can be configured to output .
[0006]
Further, when a battery 5 mounted on the self-propelled transport vehicle 1 for supplying power to the traveling motor 2 or the like is provided with a temperature sensor 6 for referring to the battery temperature, for example, the charging time determination means 7. The battery temperature sensor 6 can also be used as the temperature sensor.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a conventionally known self-propelled transport vehicle, which is equipped with a speed control device 3 for a traveling motor 2. The vehicle automatically travels along a predetermined trackless travel route 4 by various automatic steering methods. Of course, it may be a self-propelled transport vehicle that travels on a guide rail. The travel motor 2 is supplied with power from an on-board battery 5, and a temperature sensor 6 for detecting the temperature of the battery itself is attached to the battery 5, and the temperature detected by the temperature sensor 6 (battery temperature) Charging time determination means 7 for determining the charging time of the battery 5 based on electrical information such as the voltage value and current value of the battery 5 is provided.
[0008]
The self-propelled transport vehicle 1 is provided with an ultrasonic detection type obstacle detection sensor 8 that detects an obstacle in front of the traveling direction. In the illustrated example, a configuration in which a plurality (three in the illustrated example) of obstacle detection sensors 8 are arranged in parallel in the width direction of the vehicle body is shown, but the number and arrangement of the sensors are not particularly limited. Obstacle detection control means 10 is connected to these obstacle detection sensors 8 via sensor control means 9, and a deceleration command C1 and a stop command C2 output from the obstacle detection control means 10 are the speeds. An interrupt is input to the control device 3, and the traveling control of the self-propelled transport vehicle 1 based on obstacle detection is performed.
[0009]
That is, as shown in FIG. 2, the sensor control means 9 transmits the ultrasonic wave of the obstacle detection sensor 8 (continuous transmission time is about 10 ms, for example) and reception monitoring, that is, monitoring of regression ultrasonic wave reception (continuous reception). The monitoring time is, for example, about 40 ms) and is turned on / off at a constant cycle (for example, 90 to 150 ms), and is controlled at the timing at which ultrasonic transmission and reception monitoring are started simultaneously. Therefore, when the transmitted ultrasonic wave is reflected by the obstacle in the detection area, the regression ultrasonic wave from the obstacle is received and monitoring the obstacle detection signal at the time of reception monitoring started simultaneously with the transmission of the ultrasonic wave. If the obstacle continues to exist in the detection area, an obstacle detection signal is output at the time of each reception monitoring, and as a result, the period of the reception monitoring during the period in which the obstacle exists in the detection area. Thus, the obstacle detection signal is intermittently output. Further, as shown in FIG. 1, as the obstacle detection distance of the obstacle detection sensor 8, a long distance L1 and a short distance L2 are set, and a detection signal of an obstacle entering the detection area of the long distance L1, That is, a long-distance obstacle detection signal PL or an obstacle detection signal that has entered the detection area at the short distance L2, ie, a short-distance obstacle detection signal PS, is distinguished and output.
[0010]
The obstacle detection control means 10 is based on the number of inputs of the long-distance obstacle detection signal PL or the short-distance obstacle detection signal PS during reception monitoring from the sensor control means 9 and the detection temperature T of the temperature sensor 6. The control shown in the flowchart of FIG. 3 is performed.
[0011]
That is, when the detected temperature (battery temperature) T of the temperature sensor 6 is equal to or higher than the set temperature based on the determination process (S1) as to whether or not the detected temperature (battery temperature) is equal to or higher than the set temperature (for example, 40 ° C.) The determination process (S2) of whether or not the obstacle detection signal (PL / PS) is input and the determination process (S3) of whether or not the obstacle detection signal is the long-distance obstacle detection signal PL. Based on the input of the first long-distance obstacle detection signal PL, the deceleration command C1 is output to the speed control device 3 (S4), and when the first short-distance obstacle detection signal PS is input, the stop command C2 is output as the speed control device. 3 (S5). When the detected temperature (battery temperature) T of the temperature sensor 6 is lower than the set temperature, it is determined whether or not the second obstacle detection signal (PL / PS) is input from the sensor control means 9 (S6). ) And a determination process (S3) as to whether or not the obstacle detection signal is the long-distance obstacle detection signal PL, the speed of the deceleration command C1 is controlled by inputting the second long-distance obstacle detection signal PL. Output to the device 3 (S4), and a stop command C2 is output to the speed control device 3 by the second input of the short-distance obstacle detection signal PS (S5).
[0012]
Thus, as shown in FIG. 4, the speed control device 3 that has received the deceleration command C1 controls the traveling motor 2 to decelerate the traveling speed V of the self-propelled transport vehicle 1 from a high speed to a low speed, and stops the command C2. In response, the speed control device 3 controls the traveling motor 2 to stop the self-propelled transport vehicle 1.
[0013]
The battery temperature set in the obstacle detection control means 10 has been described as 40 ° C. as an example. However, the battery temperature can be arbitrarily set according to the use environment of the self-propelled transport vehicle 1 and can be freely set. It is desirable to make it adjustable. Moreover, although the temperature sensor 6 attached to the battery 5 mounted on the self-propelled transport vehicle 1 is used, even when the battery temperature sensor 6 is not provided or the battery temperature sensor 6 is provided, the dedicated temperature sensor 6 is used. A temperature sensor can be provided separately. In this case, the optimum set temperature is selected according to the mounting position of the temperature sensor. However, when detecting the ambient temperature in the factory where the self-propelled transport vehicle 1 is used, for example, the summer and the winter are distinguished. A reference temperature, for example, about 25 ° C. to 30 ° C. is set.
[0014]
Further, since the obstacle detection signal only needs to be output intermittently at a constant period, only the reception monitoring of the obstacle detection sensor may be turned on / off at a constant period, and ultrasonic transmission may be continuously performed. Furthermore, it has been explained that the speed control is performed with the first obstacle detection signal when the temperature is higher than the set temperature, and the speed control is performed with the second obstacle detection signal when the temperature is lower than the set temperature. The number of times of setting the obstacle detection signal is not limited to this example, and the number of times of setting the obstacle detection signal when performing the speed control can be arbitrarily changed.
[0015]
【The invention's effect】
The present invention can be implemented as described above, and according to the obstacle detection device for a self-propelled carriage according to the present invention, the temperature of the environment in which the self-propelled transport vehicle is used is large in summer and winter, for example. In the case where the width changes, or when the traveling route of the self-propelled transport vehicle is provided across the room and the outdoor where the temperature environment is greatly different from the outdoor such as a refrigeration / freezer room or a warm room, By setting the temperature at any point in the middle of the temperature change in the environment of use of the self-propelled transport vehicle as the set temperature, it can be used either in a low temperature atmosphere lower than the set temperature or in a high temperature atmosphere higher than the set temperature. However, as long as the sensitivity of the ultrasonic detection type obstacle detection sensor is adjusted so that normal obstacle detection is performed, the sensitivity in the high-temperature atmosphere that is opposite to the ambient temperature at the time of sensitivity adjustment is When using or in a low temperature atmosphere However, it is possible to automatically change the number of obstacle detection signals output until the actual speed control is reflected, thereby preventing the obstacle detection sensitivity from being lowered or becoming too sensitive. I can do it.
[0016]
Therefore, it is not necessary to adjust the sensitivity of the sensor according to the temperature change in the environment where the self-propelled transport vehicle is used, and the sensitivity detection according to the temperature change is not performed. The speed control is performed by detecting the equipment around the travel route too much, and the inconvenience that the transport work cannot be performed efficiently, or the collision accident occurs due to the omission of the obstacle to be detected. Inconvenience can be avoided.
[0017]
In addition, according to the structure of Claim 2, control becomes easy and according to the structure of Claim 3, it becomes unnecessary to provide a dedicated temperature sensor, and this invention can be implemented economically.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of the present invention.
FIG. 2 is a graph for explaining the operation of an ultrasonic detection type obstacle detection sensor;
FIG. 3 is a flowchart illustrating a control procedure.
FIG. 4 is a graph illustrating speed control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Self-propelled transport vehicle 2 Traveling motor 3 Speed control device 4 Traveling path 5 Battery 6 Temperature sensor 7 Battery charging time determination means 8 Sensor for detecting obstacles of ultrasonic detection system 9 Sensor control means 10 Control means C1 for detecting obstacles Deceleration command C2 Stop command PL Long-distance obstacle detection signal PS Short-distance obstacle detection signal T Temperature sensor detection temperature

Claims (3)

An obstacle detection device provided with an ultrasonic detection type obstacle detection sensor in a self-propelled transport vehicle, and performing deceleration stop control of the self-propelled transport vehicle based on an obstacle detection signal of the sensor, Sensor control means, temperature sensor, and detection temperature and obstacle detection signal of this temperature sensor that intermittently outputs an obstacle detection signal when obstacle monitoring is detected by turning ON / OFF reception monitoring for the obstacle detection sensor Based on the obstacle detection control means for outputting a speed control signal for decelerating or stopping the self-propelled transport vehicle, the obstacle detection control means, the detection temperature of the temperature sensor is less than the set temperature When the obstacle control signal is output intermittently from the sensor control means at the time, the speed control signal is output when the number of output of the obstacle detection signal reaches the set number of times. When an obstacle detection signal is output intermittently from the sensor control means when the detected temperature of the temperature sensor is equal to or higher than a set temperature, the number of output of the obstacle detection signal is set to a set number less than the set number. An obstacle detection device for a self-propelled transport vehicle that outputs the speed control signal when it reaches . When the obstacle detection signal is output intermittently from the sensor control means when the detected temperature of the temperature sensor is equal to or higher than a set temperature, the obstacle detection control means is configured to output the first obstacle detection signal. When the obstacle control signal is output intermittently from the sensor control means when the speed control signal is output and the detected temperature of the temperature sensor is lower than a set temperature, the second obstacle detection signal is output. The obstacle detection device for a self-propelled transport vehicle according to claim 1, which outputs the speed control signal . The obstacle detection device for a self-propelled transport vehicle according to claim 1 or 2, wherein the temperature sensor is also used as a battery temperature sensor for measuring a temperature of a battery mounted on the self-propelled transport vehicle.

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