Mobile object control device and mobile object control method

Abstract

To achieve highly precise travel control by calibrating vehicle body information on a moving body.SOLUTION: A moving body controller includes an input unit that inputs condition information representing a position and / or angle of a moving body, a control function unit that determines the contents of control concerning movement of the moving body on the basis of the condition information, a generation function unit that generates a driving signal which is sent to a drive unit in order to achieve the contents of control, a history recording function unit that records at least a history of the condition information, and a correction function unit that corrects the vehicle body information on the basis of a difference between a result of control represented by the history of the condition information and the contents of control.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a mobile object control device and a mobile object control method. [Background technology]

[0002] Conventionally, automated guided vehicles (AGVs) have been used in factories, logistics warehouses, and other locations for transporting parts and handling cargo. The automated guided vehicles are equipped with a route detector that detects, for example, guidelines drawn on a travel route. The automated guided vehicles can travel along the guidelines by controlling the drive wheels based on detection signals from the route detector. A mobile system disclosed in Patent Document 1 is known as a technology for controlling the autonomous movement of a mobile object to a destination. This publication describes the following: "A mobile system including a flat sign arranged according to a predetermined travel route and a mobile object that travels autonomously along the travel route. The mobile system includes: a distance and direction detection device provided on the mobile object that detects the distance and direction between the mobile object and an object within a predetermined search range by scanning a detection light within the search range; and a travel direction determination means that determines the travel direction of the mobile object based on the detection result of the distance and direction detection device. The flat sign includes a mirror surface and a diffuse reflection surface that diffusely reflects incident light at a rate higher than that of the mirror surface." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-113765 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional technologies do not take into account the calibration of vehicle body information, which can result in reduced control accuracy. For example, if there is a difference between the drive wheel diameter recognized by the control side and the actual drive wheel diameter, an error occurs between the travel distance estimated by the control side and the actual travel distance. Similarly, if there is a difference between the drive wheel mounting spacing recognized by the control side and the actual drive wheel mounting spacing, an error occurs between the turning angle estimated by the control side and the actual turning angle. Vehicle body information such as drive wheel diameter and drive wheel mounting spacing may differ from the values recognized by the control side due to, for example, individual differences or deterioration over time.

[0005] Therefore, an object of the present invention is to calibrate vehicle body information of a moving body and realize highly accurate driving control. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one representative mobile body control device of the present invention is characterized by comprising an input unit for inputting status information indicating the position and / or angle of the mobile body, a control function unit for determining control content regarding the movement of the mobile body based on the status information, a generation function unit for referencing body information of the mobile body and generating a drive signal to be given to a drive unit to realize the control content, a history recording function unit for recording at least the history of the status information, and a correction function unit for correcting the body information based on the difference between the control results indicated by the history of the status information and the control content. Furthermore, one representative mobile body control method of the present invention is characterized in that it includes an input step in which a mobile body control device inputs status information indicating the position and / or angle of the mobile body, a control step in which control content related to the movement of the mobile body is determined based on the status information, a generation step in which body information of the mobile body is referenced and a drive signal is generated to be given to a drive unit to realize the control content, a history recording step in which at least a history of the status information is recorded, and a correction step in which the body information is corrected based on the difference between the control results indicated by the history of the status information and the control content. [Effects of the Invention]

[0007] According to the present invention, vehicle body information of a moving body can be calibrated, and highly accurate driving control can be achieved. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 10 is a sequence diagram for correcting the drive wheel diameter. [Figure 6] FIG. 10 is a sequence diagram for correcting the drive wheel mounting interval. [Figure 7] 10 is a flowchart for correcting vehicle body information. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment will be described with reference to the drawings. [Example]

[0010] In this embodiment, a mobile body control device that controls a differential two-wheel drive mobile body and has a function of correcting vehicle body information will be described. A differential two-wheel drive vehicle has two opposing drive wheels that are driven independently to move straight and change direction. The diameter of the drive wheels is called the drive wheel diameter, and the distance between the drive wheels when attached to the vehicle is called the drive wheel mounting interval. The drive wheel diameter and drive wheel mounting interval are managed as part of the vehicle information. The vehicle information can include not only the drive wheel diameter and drive wheel mounting interval, but also various other parameters that indicate the dimensions of the vehicle.

[0011] In this embodiment, the drive wheel diameter and drive wheel mounting spacing are the parameters to be corrected. Both parameters are essential for controlling a moving body, and fixed values are input as parameters, such as when the moving body is manufactured. However, in reality, the drive wheel parameters fluctuate due to the influence of factors such as tolerances during manufacturing, wear, and vibration. Therefore, when using functions such as odometry that utilize vehicle body information, the larger the error, the less performance can be achieved. In this embodiment, the drive wheel diameter is corrected by utilizing the encoder values obtained from the drive wheels and the position information obtained from the position sensor, and then the drive wheel mounting spacing is corrected, thereby improving the accuracy of the vehicle body information parameters.

[0012] 1 shows a configuration diagram of a mobile body 100 of this embodiment. The mobile body 100 has a configuration in which two drive wheels 105 are attached to a vehicle body 106. The vehicle body 106 is also equipped with a position sensor 102, two encoders 103, two drive units 104, and a mobile body control device 101.

[0013] The mobile object control device 101 has an input unit 110 and an output unit 111 as an interface unit. The position sensor 102 estimates its own position using a laser scanner, a camera, etc., and outputs coordinate and angle data. For example, the position sensor 102 compares the external situation detected by the laser scanner, camera, etc. with predetermined map data, identifies coordinates on the map data and angles relative to a predetermined direction on the map data, and provides them as input to the input unit 110 of the mobile body control device 101.

[0014] The two encoders 103 are provided corresponding to the two drive wheels 105, respectively, and acquire the rotation angles of the drive wheels 105. The encoders 103 provide the acquired encoder values to the input unit 110 of the mobile body control device 101 as input.

[0015] The two drive units 104 are provided corresponding to the two drive wheels 105, respectively, and are control drivers that control the rotation of the drive wheels 105 based on drive signals output from the output unit 111 of the mobile body control device 101. The drive wheels 105 have parameters such as a drive wheel diameter 107, which is the size of the drive wheels, and a drive wheel mounting interval 108.

[0016] 2 shows a configuration diagram of the mobile body control device 101 of this embodiment. In addition to an input unit 110 and an output unit 111, the mobile body control device 101 includes a vehicle body control function unit 112, a drive signal generation function unit 113, a data logging function unit 114, a vehicle body information correction function unit 115, vehicle body information data 118, and correction data 119.

[0017] The input unit 110 receives input of state information indicating the coordinates and angle of the moving object 100. Specifically, the input of the coordinates and angle is received from the position sensor 102 and used as the state information. The input unit 110 also receives input of the encoder value from the encoder 103.

[0018] The vehicle control function unit 112 is a control function unit that determines the control content related to the movement of the moving body 100 based on the state information. The drive signal generating function unit 113 is a generating function unit that refers to the vehicle body information data 118 and generates a drive signal to be given to the drive unit 104 in order to realize the control content. For example, if the control content is the straight-line distance of the moving body 100, the drive signal generation function unit 113 generates a drive signal that specifies the rotation amount of the drive wheels by dividing the straight-line distance by the drive wheel diameter. When moving straight, the same drive signal can be applied to both drive wheels. Alternatively, if the drive wheel diameters of the two drive wheels are managed separately, drive signals to be applied to each drive wheel can be generated separately. Furthermore, if the control content is to change the direction of the moving body 100, the drive signal generation function unit 113 generates drive signals that specify different amounts of rotation for the two drive wheels. In this way, the drive signal generating function unit 113 generates a drive signal that controls the rotation of each of the drive wheels, and outputs the generated drive signal from the output unit 111 of the interface unit.

[0019] The data logging function unit 114 is a history recording function unit that stores the coordinates and angles of the state information and the encoder values for each time. The stored data is treated as correction data 119. For example, when correcting the drive wheel diameter, the data logging function unit 114 acquires data when traveling straight and uses this as correction data 119. Similarly, when correcting the drive wheel mounting spacing, the data logging function unit 114 acquires data when turning and uses this as correction data 119.

[0020] The vehicle body information correction function unit 115 is a correction function unit that corrects vehicle body information based on the difference between the control results and the control contents indicated by the history of the status information. The vehicle body information correction function unit 115 includes a drive wheel diameter correction function 116 and a drive wheel mounting interval correction function 117. The vehicle body information correction function unit 115 calculates a correction value for the vehicle body information using correction data 119 created by the data logging function unit 114 and overwrites the parameters stored in the vehicle body information data 118.

[0021] Specifically, the drive wheel diameter correction function 116 calculates the drive wheel diameter using the travel distance calculated from the coordinate history of the correction data 119 and the number of rotations calculated from the encoder value, and updates the drive wheel diameter of the vehicle body information data 118 with the calculated drive wheel diameter. Furthermore, the drive wheel mounting interval correction function 117 corrects the spacing between the drive wheels based on the difference between the change in angle of the mobile object 100 calculated from the angle history of the correction data 119 and the change in angle of the mobile object derived from the control content. For example, the drive wheel mounting interval correction function 117 calculates the angular velocity when the mobile object 100 turns from the angle history of the correction data 119, calculates the drive wheel mounting interval by dividing the speed difference between the two drive wheels 105 by the angular velocity, and updates the drive wheel mounting interval in the vehicle body information data 118 with the calculated drive wheel mounting interval.

[0022] In making the correction, it is desirable that the drive wheel diameter correction function 116 corrects the drive wheel diameter, and then the drive wheel mounting interval correction function 117 corrects the drive wheel mounting interval using the corrected drive wheel diameter. In addition, the drive wheel diameter correction function 116 corrects the diameter of the drive wheels using the history of the state information when the moving body is moving straight, and the drive wheel mounting interval correction function 117 corrects the drive wheel interval using the history of the state information when the moving body is changing direction.

[0023] 3 is an explanatory diagram of the vehicle body information data 118. In this embodiment, the vehicle body information data 118 holds the encoder value per one rotation of the drive wheel in addition to the drive wheel diameter 107 and the drive wheel mounting interval 108 as vehicle body information.

[0024] FIG. 4 is an explanatory diagram of the correction data. The correction data 119 is generated by the data logging function unit 114 and used by the vehicle information correction function unit 115. Data integration is stored in order according to integration cycles or specified timing. In the figure, the correction data 119 stores time information, coordinate information, accuracy information, and encoder values in association with each other. Note that the encoder values may be stored separately for each of the two drive wheels 105.

[0025] 5 is a sequence diagram of the correction of the drive wheel diameter. When the moving body 100 is in a driving state and the drive wheel diameter 107 is to be corrected, the vehicle control function unit 112 corrects the drive wheel diameter 107 using each function.

[0026] Specifically, first, the data logging function unit 114 logs the position coordinates, angles, and encoder values for a certain period of time. When the data logging function unit 114 finishes logging, it stores data for the period when the behavior of the mobile object 100 is straight ahead in the correction data 119. Thereafter, the drive wheel diameter correction function 116 refers to the correction data 119 and calculates the drive wheel diameter 107 using arithmetic expressions (120) to (122). The drive wheel diameter correction function 116 overwrites the drive wheel diameter data in the vehicle information data 118 with the calculated drive wheel diameter 107, and ends the correction of the drive wheel diameter.

[0027] Here, the arithmetic expressions (120) to (122) will be explained.

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number

number

[0028] Note that other methods may be used to calculate the drive wheel diameter. For example, instead of arithmetic formula (121), the following formula may be used, which finds the sum of the square of the difference between the X coordinate and the square of the difference between the Y coordinate, and then multiplies the square root of the sum: Σ((X (k+1) -X (k) ) 2 +(Y (k+1) -Y (k) ) 2 ) 1 / 2

[0029] Fig. 6 shows the sequence for correcting the drive wheel mounting interval. By first correcting the drive wheel diameter 107, it becomes possible to calculate accurate speed information, and as a result, it becomes possible to highly accurately correct the drive wheel mounting interval 108. When the vehicle 100 is in operation and the drive wheel mounting interval 108 is to be corrected, the vehicle control function unit 112 corrects the drive wheel mounting interval 108 using each function.

[0030] Specifically, first, the data logging function unit 114 logs the position coordinates, angles, and encoder values for a certain period of time. After completing the logging, the data logging function unit 114 stores data for the period during which the behavior of the mobile object 100 is turning (changing direction) in the correction data 119. Thereafter, the drive wheel mounting interval correction function 117 refers to the correction data 119 and calculates the drive wheel mounting interval 108 using arithmetic expressions (123) to (124). The drive wheel mounting interval correction function 117 overwrites the drive wheel mounting interval data in the vehicle information data 118 with the calculated drive wheel mounting interval 108, and ends the correction of the drive wheel mounting interval.

[0031] Here, the arithmetic expressions (123) to (124) will be explained.

number

number

[0032] It should be noted that other methods may be used to calculate the drive wheel mounting interval. For example, instead of the arithmetic formula (123), the following formula may be used, which calculates the speed difference between the two drive wheels and divides the calculated speed difference by the angular velocity when the vehicle turns. Drive wheel mounting distance = (speed difference between drive wheels) / angular velocity The speed of the drive wheels can be calculated from the time change in the encoder value and the drive wheel diameter. Therefore, by correcting the drive wheel diameter and then calculating the drive wheel spacing using the corrected drive wheel diameter, the drive wheel spacing can be calculated with high accuracy.

[0033] 7 is a flowchart of the correction of the vehicle body information. When correcting the vehicle body information, the mobile object control device 101 sequentially executes the following steps S131 to S138. First, the input unit 110 inputs state information indicating the coordinates and angle of the position of the moving body 100 (step S131). After that, the vehicle control function unit 112 determines the control content related to the movement of the moving body 100 based on the state information (step S132).

[0034] The drive signal generation unit 113 refers to the vehicle body information data 118 (step S133), generates a drive signal to be given to the drive unit to realize the control content (step S134), and outputs the drive signal from the output unit 111 to the drive unit 104 (step S135).

[0035] The data logging function unit 114 records the time, the status information, and the encoder value in association with each other (step S136), and determines whether to end the recording (step S137). If the recording is not to be ended (step S137; No), the process returns to step S131.

[0036] When the recording is completed (step S137; Yes), the vehicle body information correction function unit 115 corrects the vehicle body information data 118 based on the difference between the control result and the control content indicated by the history of the status information (step S138), and ends the processing.

[0037] As described above, the mobile body control device 101 disclosed in the embodiments comprises an input unit 110 for inputting status information indicating the position and / or angle of the mobile body 100, a vehicle body control function unit 112 as a control function unit that determines control content related to the movement of the mobile body 100 based on the status information, a drive signal generation function unit 113 as a generation function unit that refers to the vehicle body information of the mobile body 100 and generates a drive signal to be given to the drive unit 104 to realize the control content, a data logging function unit 114 as a history recording function unit that records at least the history of the status information, and a vehicle body information correction function unit 115 as a correction function unit that corrects the vehicle body information based on the difference between the control results indicated by the history of the status information and the control content. This configuration and operation allows for calibration of vehicle information of a moving body, thereby achieving highly accurate driving control.

[0038] Furthermore, the moving body 100 drives two opposing drive wheels 105 individually to move straight and change direction, the vehicle body information includes the diameter of the drive wheels and the spacing between the drive wheels, the generation function unit generates a drive signal to control the rotation of each of the drive wheels, the history recording function unit records an encoder value indicating the rotation state of the drive wheels in association with the status information as information corresponding to the control content, and the correction function unit corrects the diameter and / or spacing of the drive wheels using the position and / or angle history and the encoder value history. Therefore, for a differential two-wheel drive mobile body, the diameter and / or spacing of the drive wheels can be corrected.

[0039] In addition, the moving body 100 moves forward and changes direction by individually driving two opposing drive wheels 105, the vehicle information includes the spacing between the drive wheels, the input unit 110 inputs the angle of the moving body 100 relative to a predetermined reference direction as the status information, and the correction function unit corrects the spacing between the drive wheels based on the difference between the change in angle of the moving body 100 indicated by the history of the status information and the change in angle of the moving body derived from the control content. As an example, the correction function unit determines the angular velocity when the moving body changes direction from the history of the status information, divides the speed difference of the drive wheels by the angular velocity to calculate the spacing between the drive wheels, and updates the vehicle body information using the calculated spacing between the drive wheels. Therefore, the distance between the drive wheels of a differential two-wheel drive vehicle can be easily determined.

[0040] The correction function unit also calculates the diameter of the drive wheels using the travel distance calculated from the position history and the number of rotations calculated from the encoder value, and updates the vehicle body information with the calculated diameter of the drive wheels. Therefore, the drive wheel diameter of a differential two-wheel drive mobile body can be easily determined.

[0041] In addition, the correction function unit corrects the diameter of the drive wheels, calculates the speed difference of the drive wheels using the corrected diameter of the drive wheels and the encoder value, calculates the spacing between the drive wheels by dividing the calculated speed difference by the angular velocity at the time of turning of the moving body obtained from the history of the status information, and updates the vehicle body information using the calculated spacing between the drive wheels. In this way, by using the correction result of the drive wheel diameter for correcting the drive wheel mounting interval, the drive wheel mounting interval can be corrected with high precision.

[0042] The correction function unit corrects the diameter of the drive wheels using the history of the status information when the moving body 100 is moving straight, and corrects the spacing between the drive wheels using the history of the status information when the moving body 100 is changing direction. Therefore, the history of the state information can be efficiently acquired and used to correct the vehicle body information.

[0043] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0044] Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be partially or entirely implemented in hardware, for example, by designing them as integrated circuits. The above-described configurations, functions, etc. may also be implemented in software, with a processor interpreting and executing a program that implements each function. Information such as the programs, tables, and files that implement each function can be stored in a memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD. In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and do not necessarily show all the control lines and information lines in the product. In reality, it can be assumed that almost all components are interconnected.

[0045] Furthermore, in the above embodiment, correction of the drive wheel diameter and the drive wheel interval was exemplified, but if the drive wheel diameter is reliable, it is also possible to correct the encoder value from the drive wheel diameter. Furthermore, the mobile body control device does not necessarily have to be mounted on the mobile body, but may be a device that remotely controls the mobile body. Furthermore, the functions of the mobile object control device may be divided into multiple devices, which may operate as a system. [Explanation of symbols]

[0046] 100: Mobile body, 101: Mobile body control device, 102: Position sensor, 103: Encoder, 104: Drive unit, 105: Drive wheel, 106: Vehicle body, 107: Drive wheel diameter, 108: Drive wheel mounting interval, 110: Input unit, 111: Output unit, 112: Vehicle body control function unit, 113: Drive signal generation function unit, 114: Data logging function unit, 115: Vehicle body information correction function unit, 116: Drive wheel diameter correction function, 117: Drive wheel mounting interval correction function, 118: Vehicle body information data, 119: Correction data

Claims

1. an input unit for inputting state information indicating the position and / or angle of the moving object; a control function unit that determines control details regarding the movement of the moving object based on the state information; a generation function unit that references vehicle body information of the moving body and generates a drive signal to be provided to a drive unit to realize the control content; a history recording function unit that records at least a history of the state information; a correction function unit that corrects the vehicle body information based on a difference between the result of control indicated by the history of the state information and the content of the control, The moving body moves straight and changes direction by independently driving two opposing drive wheels, the vehicle body information includes a diameter of the drive wheels and a spacing between the drive wheels; the generating function unit generates a drive signal that controls rotation of each of the drive wheels; the history recording function unit records an encoder value indicating a rotation state of the drive wheels as information corresponding to the control content in association with the status information; the correction function unit corrects the diameter and spacing of the drive wheels using the history of the position and / or angle and the history of the encoder values; The correction function unit corrects the diameter of the drive wheels, calculates a speed difference of the drive wheels using the corrected diameter of the drive wheels and the encoder value, calculates a spacing between the drive wheels by dividing the calculated speed difference by the angular velocity of the moving body when changing direction obtained from the history of the status information, and updates the vehicle information using the calculated spacing between the drive wheels.

2. The mobile object control device according to claim 1, the input unit inputs an angle of the moving object with respect to a predetermined reference direction as the state information; A mobile body control device characterized in that the correction function unit corrects the spacing between the drive wheels based on the difference between the change in angle of the mobile body indicated by the history of the status information and the change in angle of the mobile body derived from the control content.

3. A mobile object control device according to claim 1, A mobile body control device characterized in that the correction function unit calculates the diameter of the drive wheel using the travel distance obtained from the position history and the number of rotations obtained from the encoder value, and updates the vehicle body information using the calculated diameter of the drive wheel.

4. A mobile object control device according to claim 1, A mobile body control device characterized in that the correction function unit corrects the diameter of the drive wheels using the history of the status information when the mobile body is moving straight, and corrects the spacing between the drive wheels using the history of the status information when the mobile body is changing direction.

5. The mobile object control device an input step of inputting state information indicating a position and / or an angle of the moving object; a control step of determining control details regarding the movement of the moving object based on the state information; a generating step of generating a drive signal to be provided to a drive unit to realize the control content by referring to vehicle body information of the moving body; a history recording step of recording at least a history of the status information; a correcting step of correcting the vehicle body information based on a difference between the result of control indicated by the history of the state information and the content of the control, The moving body moves straight and changes direction by independently driving two opposing drive wheels, the vehicle body information includes a diameter of the drive wheels and a spacing between the drive wheels; the generating step generates a drive signal that controls rotation of each of the drive wheels; the history recording step includes recording an encoder value indicating a rotation state of the drive wheels as information corresponding to the control content in association with the status information; the correcting step corrects the diameter and spacing of the drive wheels using the history of the position and / or angle and the history of the encoder values; The correction step corrects the diameter of the drive wheels, calculates a speed difference between the drive wheels using the corrected diameter of the drive wheels and the encoder value, calculates a spacing between the drive wheels by dividing the calculated speed difference by an angular velocity at the time of turning of the moving body obtained from the history of the state information, and updates the vehicle body information using the calculated spacing between the drive wheels. A mobile object control method comprising:

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