JP3628405B2 - Direction correction method and apparatus for traveling vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for correcting travel control of a vehicle that travels autonomously.
[0002]
[Prior art]
In general, an orientation sensor such as a gyro is frequently used for traveling control of an autonomous traveling vehicle such as a floor cleaning robot or an automatic guided vehicle. However, for example, when a gyro is used, the error included in the direction detected by the gyro increases with the passage of travel time due to the drift of the gyro itself and the drift of the integrator included in the signal processing circuit. To go.
[0003]
In view of this, for example, as in the apparatus disclosed in Japanese Patent Laid-Open No. 6-236212, a control technique for correcting the detection signal by causing the gyro to perform sampling at regular intervals has been proposed.
[0004]
[Problems to be solved by the invention]
The travel control device disclosed in the above publication has the following problems. When the cart is run for a long time of 30 minutes or longer using this device, errors included in the direction detected by the gyro accumulate, and there is a case where sufficient correction cannot be performed. In this travel control device, the output of the gyro is set to zero at the point where the travel of the carriage starts in FIG. However, since the error angle ΘEr of the gyro accumulates as the travel time becomes longer, the travel angle set at the start of travel cannot be maintained.
[0005]
The present invention has been made in view of the above circumstances, and by correcting an error included in a detection signal of an orientation sensor such as a gyro at regular intervals, an increase in the error can be prevented and a predetermined traveling angle can be maintained. An object of the present invention is to provide a method and apparatus for correcting the direction of a traveling vehicle.
[0006]
[Means for Solving the Problems]
The traveling vehicle direction correction device of the present invention is
Drive wheels arranged in the traveling vehicle;
Drive means for driving the drive wheels;
An azimuth sensor that detects the azimuth of the traveling vehicle and outputs an azimuth signal;
A sensor for detecting a detection object installed intermittently in the course of the travel route and outputting a detection signal;
A control unit that receives the detection signal output from the sensor and the azimuth signal output from the azimuth sensor and controls the driving unit to travel along a travel route;
The sensor is
Provided over a predetermined length near a central portion in a direction substantially orthogonal to the traveling direction of the traveling vehicle, and detecting the detection object, a deviation distance between the center of the detection object and the center of the sensor A voltage value of a corresponding magnitude, and a voltage value of a sign corresponding to a direction in which the center of the detection object is shifted with reference to the center of the sensor is output as the detection signal,
The controller is
While the sensor is not detecting the detection object, the driving means is controlled using the direction signal output by the direction sensor,
While the sensor detects the detection object and outputs the detection signal, the sensor is caused to run while controlling the rotational speed of the driving means so that the center of the sensor coincides with the center of the detection object. The azimuth signal output from the azimuth sensor is set to the same value as at the start of traveling.
[0007]
The sensor may be provided near the front center of the traveling vehicle.
[0009]
Moreover, it is desirable that the detection object has a bifurcated portion where the traveling vehicle enters.
[0010]
The direction correction method for a traveling vehicle of the present invention includes:
In the traveling vehicle direction correction method for controlling the traveling vehicle to travel along a predetermined traveling route,
The detection object is intermittently installed in the middle of the travel route, and the traveling vehicle is provided over a predetermined length near the center in the direction substantially orthogonal to the traveling direction, and the presence of the detection object is present. A sensor for detecting presence / absence and a relative displacement distance from the detection object, and an orientation sensor for detecting an orientation,
Determining whether the sensor has detected the presence of the detection object;
While the sensor does not detect the presence of the detection object, controlling the traveling vehicle to travel along a travel route based on the direction detected by the direction sensor;
While the sensor detects the presence of the detection target, the voltage value is a magnitude corresponding to the deviation distance detected by the sensor between the center of the detection target and the center of the sensor. And a vehicle traveling so that the center of the sensor coincides with the center of the detection object on the basis of a voltage value of a sign corresponding to a direction in which the center of the detection object is shifted with respect to the center of the sensor. And a step of setting the azimuth signal output from the azimuth sensor to the same value as at the start of running.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows the configuration of the direction correction apparatus according to this embodiment, and FIG. 2 shows the configuration of a traveling vehicle equipped with this apparatus.
[0012]
As shown in FIG. 2, the right wheel 12a and the left wheel 12b are arranged on the traveling vehicle 10 that is self-propelled in the direction of the arrow A, and are rotated by the right drive motor 11a and the left drive motor 11b, respectively. The right drive motor 11a and the left drive motor 11b are driven by the right driver 15a and the left driver 15b. The control device 16 controls the right driver 15a and the left driver 15b according to the detection results of the direction sensor 18, the front obstacle sensors 17a, 17b and 17c, the magnetic guide sensor 44, the right distance sensor 14a and the left distance sensor 14b. .
[0013]
FIG. 1 shows the configuration of the direction correction device including the internal configuration of the control device 16. The control unit 16 includes interfaces 19a to 19d, a main controller 20, a counter 21, and an AD converter 22. The front obstacle sensors 17a, 17b, and 17c are provided at the front center and both sides of the traveling vehicle 10 as shown in FIG. 2, and when the obstacle is detected, the detection signal is input to the interface 19a.
[0014]
The azimuth sensor 18 detects the traveling azimuth of the traveling vehicle 10 with respect to the reference azimuth using, for example, a gyro and inputs an azimuth detection signal to the interface 19b. The operation panel 23 inputs information input by the operator to the interface 19b.
[0015]
The magnetic guide sensor 44 is attached near the front center of the traveling vehicle 10 and detects the lateral displacement distance from the magnetic tape 51 and the presence / absence of the magnetic tape 51 as will be described later. Input to the interface 19b.
[0016]
The interface 19a receives signals output from the front obstacle sensors 17a to 17c, performs necessary processing such as amplification, and supplies the processed signals to the main controller 20. The interface 19 b receives signals from the direction sensor 18, the operation panel 23, and the magnetic guide sensor 44, performs amplification and the like, and supplies the amplified signal to the main controller 20. Here, the magnetic guide sensor 44 inputs a signal indicating the result of detecting the presence or absence of the magnetic tape 51 to the interface 19b. This signal is a digital signal having a value of “1” or “0”. Further, when the magnetic guide sensor 44 detects the presence of the magnetic tape 51, the magnetic guide sensor 44 detects a relative shift distance from the magnetic tape 51, and sends an analog signal indicating the shift distance to the A / D converter 22. input.
[0017]
As shown in FIG. 3, the magnetic guide sensor 44 detects a shift amount x between the center line of the magnetic tape 51 and the center of the magnetic guide sensor 44 when the traveling vehicle 10 travels in the direction of arrow A. To do. A voltage as shown in FIG. 4 is output from the magnetic guide sensor 44. When the center of the magnetic tape 51 is shifted to the left as shown in FIG. 3 from the center of the magnetic guide sensor 44 (when the center of the traveling vehicle 10 is shifted to the right from the center of the magnetic tape 51), it is negative. When a voltage is output and is shifted to the right (when the center of the traveling vehicle 10 is shifted to the left from the center of the magnetic tape 51), a positive voltage is output, and each voltage level becomes an absolute value of the shift amount x. It is proportional. In the present embodiment, the magnetic guide sensor 44 has a width of 200 mm, and the magnetic tape has a width of 50 mm. The deviation in the left-right direction is set to output in proportion to the deviation within a range of 50 mm, and to output a constant value in the range of 50 to 120 mm.
[0018]
The A / D converter 22 converts this analog signal into a digital signal and outputs it to the main controller 20. The main controller 20 stores the presence / absence of the magnetic tape 44 detected by the magnetic guide sensor 44 and the shift distance when the magnetic tape 44 is present in the internal memory.
[0019]
Information related to the travel distance is also input to the main controller 20. The right distance sensor 14a detects the rotation of the rotation shaft of the right drive motor 11a with an encoder or the like, and the left distance sensor 14b detects the rotation of the rotation shaft of the left drive motor 11b with an encoder or the like and inputs it to the counter 21. . The counter 21 calculates the travel distance between the right wheel 12a and the left wheel 12b from the number of rotations within a predetermined time, and outputs it to the main controller 20.
[0020]
The main controller 20 outputs a control signal to the interface 19c based on the information given from the interfaces 19a and 19b and the counter 21. The interface 19c amplifies this control signal and gives it to the right driver 15a and the left driver 15b. The right driver 15a and the left driver 15b control the operations of the right drive motor 11a and the left drive motor 11b based on this control signal. As described above, the shift distance from the magnetic tape 51 detected by the magnetic guide sensor 44 is input to the main controller 20. The main controller 20 performs proportional control or the like according to the deviation distance, and outputs signals for controlling the rotational speeds of the right drive motor 11a and the left drive motor 11b so that the magnetic guide sensor 44 is aligned with the center of the magnetic tape 51. Output to the interface 19c. Further, the azimuth sensor 18 is reset, and the azimuth angle indicated by the azimuth detection signal is set to 0 degrees, which is the same as at the start of traveling.
[0021]
In addition, the main controller 20 provides a cleaning control signal to the cleaning unit controller 33 via the interface 19d.
[0022]
FIG. 5 shows the relationship between the deviation distance x, the rotational speed VR of the right drive motor 12a, and the rotational speed VL of the left drive motor 12b. As shown in this figure, when the center of the magnetic tape 51 is shifted from the center of the magnetic guide sensor 44 by x in the right direction, the rotational speed VL of the left drive motor 12b is set so that x becomes zero. Is set relatively higher than the rotational speed VR of the right drive motor 12a.
[0023]
FIG. 6 shows the relationship between the shift distance x between the center of the magnetic tape 51 and the center of the magnetic guide sensor 44 and the rotational speed of the left drive motor 12b. When the center of the magnetic tape 51 is shifted to the left by the distance x from the center of the magnetic guide sensor 44, the rotation speed is decreased by an amount proportional to the shift distance x. When the shift distance x in the left direction is 50 mm or more, the rotation speed is constant at R2. When it shifts to the right, the maximum rotation speed R1 is maintained.
[0024]
Similarly, FIG. 7 shows the relationship between the rotational speed of the right drive motor 12 a and the shift distance x between the center of the magnetic tape 51 and the center of the magnetic guide sensor 44. When the center of the magnetic tape 51 is shifted leftward from the center of the magnetic guide sensor 44, the right drive motor 12a is constant at the maximum rotation speed R1. On the contrary, when it shifts to the right, it decreases at a speed corresponding to the shift distance x, and when it shifts by 50 mm or more, it becomes constant at the minimum rotation speed R2.
[0025]
The magnetic tape 51 does not need to be provided over the entire travel route. For example, the magnetic tape 51 having a length of 2.5 m is installed on the path through which the traveling vehicle passes every 30 minutes of traveling. As shown in FIG. 8, the magnetic tape 51 has an inverted Y-shape toward the traveling direction in which the traveling portion of the traveling vehicle 10 is expanded into a bifurcated shape. Accordingly, even when the traveling vehicle 10 is displaced larger than the width of the magnetic tape 51 as indicated by the arrow A1, the direction is corrected so as to coincide with the center of the magnetic tape 51 as indicated by the arrow A2, and the arrow A3 is corrected. Thus, it can be made to run in the direction that coincides with the magnetic tape 51.
[0026]
Here, since the magnetic tape 51 is set on the floor surface at regular intervals, traveling control is performed using the direction sensor 18 such as a gyro while the magnetic tape 51 is not installed. Therefore, it is necessary to switch the traveling control by the magnetic tape guidance and the traveling control by the direction sensor in the control unit 16.
[0027]
The operation procedure in this case is shown in FIG. In step 101, the direction sensor 18 determines whether or not the traveling direction of the traveling vehicle 10 is 0 degrees with respect to the reference direction. If the vehicle is not traveling in the 0 degree direction, the process proceeds to step 104 and travels with control based on the direction detection of the direction sensor 18. In step 105, it is determined whether or not the vehicle has traveled the set distance. If the vehicle has not traveled, the process returns to step 101. If the vehicle has traveled, the vehicle is stopped in step 106.
[0028]
If it is determined in step 101 that the heading is proceeding in the 0 degree direction, it is determined in step 102 whether or not the magnetic tape 51 has been detected. When the magnetic guide sensor 44 does not detect the magnetic tape 51, the process proceeds to step 104, and the traveling control using the direction sensor 18 is performed as described above. If the magnetic guide sensor 44 detects the magnetic tape 51, the process proceeds to step 103. The magnetic guide sensor 44 detects the deviation distance from the magnetic tape 51 and controls the deviation distance to be zero. In step 103, the direction sensor 18 is reset and its output is set to 0 degrees.
[0029]
According to the present embodiment, the traveling control based on the detection of the azimuth sensor 18 is usually performed, the magnetic tape installed on the floor surface is detected at regular intervals, and the relative relationship between the magnetic tape and the traveling vehicle is detected. The traveling direction can be corrected so that the deviation distance becomes zero. For this reason, even when the travel time is long, it is possible to prevent the errors included in the direction detection signal of the direction sensor 18 from being accumulated and greatly deviating.
[0030]
Further, it is not necessary to install the magnetic tape 51 on all the running surfaces, and it is only necessary to apply the magnetic tape 51 at regular intervals, so that the construction is easy. Furthermore, since it is only necessary to attach the magnetic tape 51 at regular intervals so as to indicate the direction to travel, the travel route can be easily changed.
[0031]
The above-described embodiment is an example and does not limit the present invention. For example, in the present embodiment, the magnetic tape is detected by a magnetic guide sensor. However, the present invention is not limited to such a combination, and any detection target that indicates the direction in which the vehicle should travel may be installed on the floor surface and detected by a sensor to correct the traveling direction. For example, a light reflecting tape that reflects light may be attached to the floor surface, or a light reflecting paint may be applied to the floor surface, and this may be detected by an optical sensor. Furthermore, an ultraviolet reflective tape can be affixed, or an ultraviolet reflective paint can be applied and detected by an ultraviolet detection sensor.
[0032]
In this embodiment, the operation of correcting the accumulated error of the azimuth sensor to zero by detecting a magnetic tape or the like is performed only when traveling in the 0 degree direction, but in the case of the 180 degree direction or 0 degree. Such correction may be performed when traveling in the direction or when traveling in any direction of 180 degrees.
[0033]
【The invention's effect】
As described above, the direction correction method and apparatus for a traveling vehicle according to the present invention detect a detection object provided in the middle of the traveling route by a sensor, and the deviation from the traveling direction of the traveling vehicle becomes zero. By adding correction in this way, accumulation of azimuth detection errors of the azimuth sensor can be prevented, and accurate running control is possible even during long-time running.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a traveling vehicle direction correcting device according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a traveling vehicle equipped with the traveling correction device.
FIG. 3 is an explanatory diagram showing a relative displacement distance x between a magnetic guide sensor and a magnetic tape in the travel correction device.
4 is a graph showing the relationship between the deviation distance x shown in FIG. 3 and the output voltage of the magnetic guide sensor.
FIG. 5 is an explanatory diagram showing the relationship between the relative displacement distance x between the magnetic guide sensor and the magnetic tape and the rotational speeds VL and VR of the left and right drive motors.
6 is a graph showing the relationship between the deviation distance x shown in FIG. 3 and the drive rotational speed of the left drive motor in the travel correction device.
7 is a graph showing the relationship between the deviation distance x shown in FIG. 3 and the drive rotational speed of the right drive motor in the travel correction device.
FIG. 8 is an explanatory diagram showing a state in which a traveling direction of a traveling vehicle is corrected by detecting a magnetic tape affixed to the floor surface.
FIG. 9 is a flowchart showing a traveling direction correction using a magnetic tape and a traveling control switching operation using an azimuth sensor by the traveling correction device.
FIG. 10 is an explanatory view showing a state in which errors in the running angle accumulate as the vehicle runs in a conventional self-propelled vehicle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Traveling vehicle 11a Right drive motor 11b Left drive motor 12a Right drive wheel 12b Left drive wheel 14a Right distance sensor 14b Left distance sensor 15a Right driver 15b Left driver 17a-17b Front obstacle sensor 18 Direction sensor 19a-19d Interface 20 Main controller 21 Counter 22 A / D converter 23 Operation panel 33 Cleaning unit controller 44 Magnetic guide sensor 51 Magnetic tape 61, 62 Wall

Claims (4)

Drive wheels arranged in the traveling vehicle;
Drive means for driving the drive wheels;
An azimuth sensor that detects the azimuth of the traveling vehicle and outputs an azimuth signal;
A sensor for detecting a detection object installed intermittently in the course of the travel route and outputting a detection signal;
A control unit that receives the detection signal output from the sensor and the azimuth signal output from the azimuth sensor and controls the driving unit to travel along a travel route;
The sensor is
Provided over a predetermined length near a central portion in a direction substantially orthogonal to the traveling direction of the traveling vehicle, and detecting the detection object, a deviation distance between the center of the detection object and the center of the sensor A voltage value of a corresponding magnitude, and a voltage value of a sign corresponding to a direction in which the center of the detection object is shifted with reference to the center of the sensor is output as the detection signal,
The controller is
While the sensor is not detecting the detection object, the driving means is controlled using the direction signal output by the direction sensor,
While the sensor detects the detection object and outputs the detection signal, the sensor is caused to run while controlling the rotational speed of the driving means so that the center of the sensor coincides with the center of the detection object. A direction correction device for a traveling vehicle, wherein the direction signal output from the direction sensor is set to the same value as that at the start of traveling. 2. The traveling vehicle direction correction device according to claim 1, wherein the sensor is provided in the vicinity of a front center portion of the traveling vehicle. The traveling vehicle direction correction device according to claim 1 or 2, wherein the detection object has a bifurcated portion where a traveling vehicle enters. In the traveling vehicle direction correction method for controlling the traveling vehicle to travel along a predetermined traveling route,
The detection object is intermittently installed in the middle of the travel route, and the traveling vehicle is provided over a predetermined length near the center in the direction substantially orthogonal to the traveling direction, and the presence of the detection object is present. A sensor for detecting presence / absence and a relative displacement distance from the detection object, and an orientation sensor for detecting an orientation,
Determining whether the sensor has detected the presence of the detection object;
While the sensor does not detect the presence of the detection object, controlling the traveling vehicle to travel along a travel route based on the direction detected by the direction sensor;
While the sensor detects the presence of the detection target, the voltage value is a magnitude corresponding to the deviation distance detected by the sensor between the center of the detection target and the center of the sensor. And a vehicle traveling so that the center of the sensor coincides with the center of the detection object on the basis of a voltage value of a sign corresponding to a direction in which the center of the detection object is shifted with respect to the center of the sensor. A direction correction method for a traveling vehicle, comprising: controlling the traveling of the vehicle and setting an azimuth signal output from the azimuth sensor to the same value as at the start of traveling.

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