Calibration device and transport robot equipped therewith

Abstract

To provide a calibration device capable of performing calibration of an object to be driven being a calibration object, and a transfer robot with the calibration device.SOLUTION: According to the present disclosure, a calibration device detects transition of one side of non-detection from detection of a detection object by a sensor, and detection from the non-detection by making a drive object slide or rotate in a second direction opposite from a first direction at a second speed slower than a first speed, and set the position of the drive object at timing of detecting the transition of the other as a reference position in the case of detecting transition of the other of the non-detection from the detection of the detection object by the sensor, and the detection from the non-detection by making the detection object slide or rotate in the first direction at the first speed.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a calibration device and a transport robot equipped with the same.

Background Art

[0002] Generally, in order to achieve highly accurate operation by a driven object driven by a motor or the like, it is required to accurately perform calibration of the driven object. In other words, it is required to accurately set the reference position of the driven object. For example, Patent Document 1 discloses a device that detects by electrical or optical means that a diaphragm body movable within a predetermined range along one direction is disposed at a reference position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the device disclosed in Patent Document 1 has a problem that when there is a width in the detection range of the diaphragm body detected by electrical or optical means, the reference position cannot be accurately detected. That is, the device disclosed in Patent Document 1 has a problem that calibration cannot be accurately performed.

[0005] The present disclosure has been made in view of the above background, and an object thereof is to provide a calibration device and a transport robot equipped with the same that can accurately perform calibration of a driven object that is a calibration target.

Means for Solving the Problems

[0006] The calibration device according to this disclosure comprises: a drive object configured to be slidable or rotatable; a housing to which the drive object is mounted; a detection object installed on one of these; a sensor installed on the other of the drive object and the housing and capable of detecting the detection object; and a setting unit that sets a reference position of the drive object in the housing according to the detection status of the detection object by the sensor. The setting unit, when it detects one of the transitions of the detection object by the sensor from detection to undetection, or from undetection to detection, by sliding or rotating the drive object in a first direction at a first speed, the setting unit detects the other transition of the detection object by the sensor from detection to undetection, or from undetection to detection, by sliding or rotating the drive object in a second direction opposite to the first direction at a second speed slower than the first speed, and sets the position of the drive object at the timing when the other transition is detected as the reference position. This calibration device can accurately set the reference position of the drive object even when there is a wide range in the detection range of the detection object detected by the sensor. In other words, this calibration device can accurately calibrate the driven object being calibrated, even when the detection range of the object detected by the sensor has a wide range.

[0007] The object to be detected is a mechanical stopper, and the sensor may include a pressure sensor that detects whether or not it has come into contact with the mechanical stopper, and a spring that absorbs the impact when the pressure sensor comes into contact with the mechanical stopper.

[0008] The sensor may also be a photo reflector.

[0009] The transport robot according to this disclosure comprises the calibration device described above, the object to be driven, and a housing. This transport robot can accurately set the reference position of the object to be driven even when the detection range of the object detected by the sensor has a wide range.

[0010] The calibration device may further include a drive unit for driving the object to be driven, and the calibration device may set the reference position of the object to be driven by sliding or rotating the object to be driven with respect to the drive unit. [Effects of the Invention]

[0011] According to this disclosure, it is possible to provide a calibration device and a transport robot equipped therewith that can accurately perform calibration of a driven object that is the target of calibration. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic perspective view showing the appearance of a transport robot to which the calibration device according to Embodiment 1 is applied. [Figure 2] This is a schematic perspective view showing a part of a transport robot to which the calibration device according to Embodiment 1 is applied. [Figure 3] This is a schematic perspective view showing a part of a transport robot to which the calibration device according to Embodiment 1 is applied. [Figure 4] This is a schematic plan view showing a part of a transport robot to which the calibration device according to Embodiment 1 is applied. [Figure 5] This is a flowchart showing the operation of the calibration device according to Embodiment 1. [Figure 6] This is a schematic plan view illustrating the operation of the calibration device according to Embodiment 1. [Figure 7] This is a schematic plan view showing a part of a transport robot to which the calibration device according to Embodiment 1 is applied. [Modes for carrying out the invention]

[0013] The present invention will be described below through embodiments of the invention, but the invention claimed is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means of solving the problem. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary.

[0014] <Embodiment 1> Figure 1 is a schematic perspective view showing the external appearance of a transport robot to which the calibration device according to Embodiment 1 is applied. Figures 2 and 3 are schematic perspective views showing a part of the transport robot according to Embodiment 1. The transport robot according to this embodiment is an autonomous mobile robot capable of automatically transporting a tray placed on a shelf or the like at a starting point, placing it on the top plate, to a destination, and then transferring it to a shelf or the like at the destination. Here, the calibration device applied to the transport robot according to this embodiment can accurately set the reference position of the drive target even when the detection range of the object detected by the sensor has a wide range. In other words, the calibration device according to this embodiment can accurately calibrate the drive target, which is the object to be calibrated, even when the detection range of the object detected by the sensor has a wide range. A detailed explanation follows below.

[0015] The transport robot 100 according to this embodiment comprises at least a housing 101, wheels 102, a top plate 103, a storage compartment 104, and a calibration device 120. The transport robot 100 also comprises, for each object to be driven, a motor (actuator) for driving the object and an encoder for measuring the angle information of the motor, etc.

[0016] The housing 101 supports the top plate 103 and the storage compartment 104, and also houses the battery, the motor that rotates the wheels 102, and the control device that controls the operation of the transport robot 100.

[0017] The top plate 103 is supported by the housing 101 via a lifting shaft 107 whose axial direction is the vertical direction (z-axis direction). Here, the top plate 103 is configured to be slidable along the vertical direction by the lifting shaft 107 expanding and contracting along the vertical direction. That is, the top plate 103 is configured to be liftable. The transport robot 100 is provided with a first motor and a first encoder for the vertical expansion and contraction process of the lifting shaft 107. The first motor drives the lifting shaft 107 to expand and contract in the vertical direction. The first encoder measures angle information and the like of the first motor. The calibration device 120 performs vertical calibration of the lifting shaft 107 which is the driving object of the first motor. In other words, the calibration device 120 sets the reference position (initial position) in the vertical direction of the lifting shaft 107. The method for vertical calibration of the lifting shaft 107 by the calibration device 120 will be described later.

[0018] Also, the top plate 103 is configured to be rotatable along the horizontal plane (xy plane) with the lifting shaft 107 as the rotation axis. The transport robot 100 is provided with a second motor and a second encoder for the rotation process of the lifting shaft 107. The second motor drives the lifting shaft 107 to rotate. The second encoder measures angle information and the like of the second motor. The calibration device 120 performs calibration of the rotation angle of the lifting shaft 107 which is the driving object of the second motor. In other words, the calibration device 120 sets the reference position of the rotation angle of the lifting shaft 107. The method for calibration of the rotation angle of the lifting shaft 107 by the calibration device 120 will be described later.

[0019] Furthermore, the top plate 103 is configured to be slidable horizontally by the linear motion axis moving along the horizontal direction. The transfer robot 100 is provided with a third motor and a third encoder for the horizontal movement process of the linear motion axis. The third motor drives the linear motion axis to move it horizontally. The third encoder measures the angle information etc. of the third motor. The calibration device 120 performs horizontal calibration of the linear motion axis for the sliding of the top plate 103, which is the object driven by the third motor. The method for horizontal calibration of the linear motion axis for the sliding of the top plate 103 by the calibration device 120 is the same as the horizontal calibration of the linear motion axis 109 for the sliding of the hook 109 by the calibration device 120, which will be described later.

[0020] The top plate 103 has a rectangular planar shape and is formed to be able to place conveyed objects such as trays. An entrance and exit of the hook 108 are provided on one of the four side surfaces of the top plate 103. The hook 108 is configured to be able to protrude in a direction perpendicular to the side surface where the entrance and exit is located from this entrance and exit. The transfer robot 100 can move the conveyed object hooked on the hook 108 from the top plate 103 to the storage section 104 or an external shelf, or move it from the storage section 104 or an external shelf to the top plate 103 by hooking the conveyed object on the hook 108 and moving the linear motion axis 109 to which the hook 108 is attached horizontally. Also, the transfer robot 100 can hook the hook 108 on the conveyed object or remove the hook 108 from the conveyed object by rotating the hook 108 with the linear motion axis 109 as the rotation axis. Hereinafter, among the four sides of the top plate 103, the side where the entrance and exit of the hook 108 is provided on the side surface is referred to as the receiving and delivering port of the conveyed object on the top plate 103.

[0021] The transport robot 100 is equipped with a fourth motor and a fourth encoder for the horizontal movement of the linear motion axis 109. The fourth motor drives the linear motion axis 109 to move it horizontally. The fourth encoder measures angle information of the fourth motor. The calibration device 120 performs horizontal calibration of the linear motion axis 109, which is the object driven by the fourth motor. In other words, the calibration device 120 sets the horizontal reference position of the linear motion axis 109. The method of horizontal calibration of the linear motion axis 109 by the calibration device 120 will be described later.

[0022] Furthermore, the transport robot 100 is equipped with a fifth motor and a fifth encoder for the rotation of the linear motion axis 109. The fifth motor drives and rotates the linear motion axis 109. The fifth encoder measures angle information of the fifth motor. The calibration device 120 performs calibration of the rotation angle of the linear motion axis 109, which is the object driven by the fifth motor. In other words, the calibration device 120 sets the reference position of the rotation angle of the linear motion axis 109. The method of calibration of the rotation angle of the linear motion axis 109 by the calibration device 120 is the same as the method of calibration of the rotation angle of the lifting axis 107 by the calibration device 120.

[0023] For example, when goods are to be transferred between the top plate 103 and an external shelf, first, the top plate 103 is raised and lowered to match the height of the external shelf. Then, the top plate 103 rotates so that its transfer opening faces the external shelf. Next, the top plate 103 slides toward the external shelf, connecting the top plate 103 and the external shelf. Finally, the goods are transferred between the top plate 103 and the external shelf using the hook 108.

[0024] Furthermore, when goods are to be transferred between the top plate 103 and the storage unit 104, first, the top plate 103 is raised and lowered to match the height of the storage unit 104. Then, the top plate 103 rotates so that its transfer opening faces the storage unit 104. After that, the top plate 103 slides toward the storage unit 104, connecting the top plate 103 and the storage unit 104. Finally, the goods are transferred between the top plate 103 and the storage unit 104 using the hook 108.

[0025] Here, in the case of the first to fifth encoders, if the power supply to the transport robot 100 is shut down, the stored angle information will be undefined. Therefore, when the transport robot 100 is powered on, it is necessary to perform calibration (setting of reference position) of the objects driven by the first to fifth motors. Accordingly, the calibration device 120 performs calibration of each driven object when the power is turned on.

[0026] The operation of the calibration device 120 will be explained below using Figures 4 to 6. Figure 4 is a schematic plan view showing a part of the transport robot 100. Figure 4 shows the top plate 103, hook 108, linear motion axis 109, and calibration device 120. Figure 5 is a flowchart showing the operation of the calibration device 120. Figure 6 is a schematic plan view for explaining the operation of the calibration device 120. The contents of steps S101 to S105 in Figure 6 correspond to the processing results of steps S101 to S105 in Figure 5, respectively. Here, we will explain using the case where the calibration device 120 performs horizontal calibration of the linear motion axis 109, to which the hook 108 is attached, which is the object to be driven.

[0027] In the example shown in Figure 4, the calibration device 120 comprises a detection target object 131, a sensor 132, and a setting unit 133. The detection target object 131 has, for example, a specific shape, pattern, or color, and is attached to the rear end of the linear motion shaft 109. The sensor 132 is, for example, a photo reflector and is attached to the top plate 103 (housing side). The sensor 132 is configured to detect the detection target object 131 located within the detection range A1. Note that the mounting locations of the sensor 132 and the detection target object 131 may be reversed.

[0028] First, in the calibration device 120, the setting unit 133 uses a motor to slide the linear motion axis 109, which is the target of calibration, at a speed v1 in the direction that stores the hook 108 inside the top plate 103 (negative direction of the y-axis) (step S101). Then, the setting unit 133 detects the transition from undetected to detected state of the object to be detected 131 by the sensor 132 (step S102). However, especially when the speed v1 is fast, the timing of the detection of the transition from undetected to detected state of the object to be detected 131 by the sensor 132 is delayed, causing the object to be detected 131 to move inside the detection range A1 of the sensor 132.

[0029] Next, the setting unit 133 slides the linear motion axis 109, which is the target of calibration, in the opposite direction (positive direction of the y-axis) at a speed v2 slower than speed v1 (step S103). Then, the setting unit 133 detects the transition from detection of the object 131 by the sensor 132 to undetected (step S104).

[0030] Then, the setting unit 133 sets the position of the linear motion axis 109 as the reference position at the timing when the sensor 132 detects the transition from detecting the object 131 to not detecting it (step S105). Here, since the speed v2 is slower than the speed v1, the timing difference in the detection of the transition from detecting the object 131 to not detecting it by the sensor 132 is small. Therefore, the calibration device 120 can set the horizontal reference position of the linear motion axis 109, which is the target of calibration, with high accuracy and speed. In other words, the calibration device 120 can perform horizontal calibration of the linear motion axis 109 with high accuracy and speed.

[0031] Next, we will further explain the operation of the calibration device 120 using Figure 2. Here, we will explain using the example of the calibration device 120 performing vertical calibration of the lifting axis 107 that raises and lowers the top plate 103, which is the object to be driven.

[0032] In the example shown in Figure 2, the calibration device 120 comprises a detection target object 121, a sensor 122, a setting unit 123, and a spring 124. The detection target object 121 is a mechanical stopper attached to the housing 101. The sensor 122 is a pressure sensor that detects whether or not it has come into contact with the mechanical stopper, and is attached to the lifting shaft 107. The sensor 122 is also provided with a spring 124 that absorbs the impact when the sensor 122 comes into contact with the mechanical stopper. Note that the mounting locations of the sensor 122 and the detection target object 121 may be reversed.

[0033] The vertical calibration of the lifting axis 107 using the calibration device 120 is basically the same as the horizontal calibration of the linear motion axis 109 using the calibration device 120.

[0034] Specifically, in the calibration device 120, the setting unit 123 uses a motor to slide the lifting shaft 107, which is the object to be calibrated, at a speed v1 in the direction that lowers the top plate 103 (negative direction of the z axis). The setting unit 123 then detects the transition from undetected to detected object 121 by the sensor 122. However, especially when the speed v1 is fast, the timing of the sensor 122's detection of the transition from undetected to detected object 121 is delayed, so even after the sensor 122 has made contact with the object 121, the lifting shaft 107 continues to descend due to the absorption of the spring 124.

[0035] Next, the setting unit 123 slides the lifting axis 107, which is the target of calibration, in the opposite direction (positive z-axis direction) at a speed v2 slower than speed v1. Then, the setting unit 123 detects the transition from detection to undetection of the object 121 detected by the sensor 122.

[0036] The setting unit 123 then sets the position of the lifting shaft 107 as the reference position at the moment when the sensor 122 detects the transition from detecting the object 121 to not detecting it. Here, since the speed v2 is slower than the speed v1, the timing difference in the detection of the transition from detecting the object 121 to not detecting it by the sensor 122 is small. Therefore, the calibration device 120 can accurately and quickly set the vertical reference position of the lifting shaft 107, which is the target of calibration. In other words, the calibration device 120 can accurately and quickly perform vertical calibration of the lifting shaft 107.

[0037] Next, the operation of the calibration device 120 will be further explained using Figure 7. Figure 7 is a schematic plan view showing a part of the transport robot 100. Figure 7 shows the housing 101, the lifting axis 107, and the calibration device 120. Here, we will explain using the example of the calibration device 120 performing calibration of the rotation angle of the lifting axis 107, which is the object to be driven.

[0038] In the example shown in Figure 7, the calibration device 120 comprises a detection target object 141, a sensor 142, and a setting unit 143. The detection target object 141 is mounted on the lifting shaft 107. The sensor 142 is, for example, a photoreflector and is mounted on the housing 101. The sensor 142 is configured to detect the detection target object 141 located within the detection range A2. Note that the mounting locations of the sensor 142 and the detection target object 141 may be reversed.

[0039] First, in the calibration device 120, the setting unit 143 uses a motor to rotate the lifting shaft 107, which is the object to be calibrated, counterclockwise at a speed v1. The setting unit 143 then detects the transition from undetected to detected object 141 by the sensor 142. However, especially when the speed v1 is fast, the timing of the sensor 142's detection of the transition from undetected to detected object 141 is delayed, causing the object 141 to move inside the detection range A2 of the sensor 142.

[0040] Next, the setting unit 143 rotates the lifting axis 107, which is the target of calibration, clockwise at a speed v2 slower than speed v1. Then, the setting unit 143 detects the transition from detection of the object 141 by the sensor 142 to undetected.

[0041] The setting unit 143 then sets the position of the lifting shaft 107 at the moment when the sensor 142 detects the transition from detecting the object 141 to not detecting it as the reference position. Here, since speed v2 is slower than speed v1, the timing difference in the detection of the transition from detecting the object 141 to not detecting it by the sensor 142 is small. Therefore, the calibration device 120 can accurately and quickly set the reference position of the rotation angle of the lifting shaft 107, which is the target of calibration. In other words, the calibration device 120 can accurately and quickly perform the calibration of the rotation angle of the lifting shaft 107.

[0042] Thus, the calibration device according to this disclosure can accurately set the reference position of the driven object even when the detection range of the object detected by the sensor has a wide range. In other words, the calibration device according to this disclosure can accurately calibrate the driven object that is the target of calibration. Furthermore, the calibration device according to this disclosure is not limited to applications to transport robots, but can be applied to any device or system that requires calibration.

[0043] The present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention.

[0044] For example, in this embodiment, the calibration device 120 was described as detecting the transition from undetected to detected by the sensor while sliding or rotating the calibration target in a first direction, and then detecting the transition from detected to undetected by the sensor while sliding or rotating in a second direction opposite to the first direction, but it is not limited to this. The calibration device 120 may be configured to detect the transition from detected to undetected by the sensor while sliding or rotating the calibration target in a first direction, and then detecting the transition from undetected to detected by the sensor while sliding or rotating in a second direction opposite to the first direction.

[0045] Furthermore, this disclosure makes it possible to implement some or all of the control processing in the calibration device by having a CPU (Central Processing Unit) execute a computer program.

[0046] The program described above includes, when loaded into a computer, a set of instructions (or software code) for causing the computer to perform one or more of the functions described in the embodiments. The program may be stored in a non-temporary computer-readable medium or a physical storage medium. Examples, but not limited to, include RAM (Random-Access Memory), ROM (Read-Only Memory), flash memory, SSD (Solid-State Drive), or other memory technologies, CD-ROM, DVD (Digital Versatile Disc), Blu-ray® disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted over a temporary computer-readable medium or a communication medium. Examples, but not limited to, include temporary computer-readable medium or a communication medium that includes electrically, optically, acoustically, or otherwise propagating signals. [Explanation of Symbols]

[0047] 100 Transport Robots 101 cabinets 102 wheels 103 Top plate 104 Storage compartment 107 Lifting shaft 108 hooks 109 Linear shaft 120 Calibration device 121 Detectable object 122 Sensor (Pressure Sensor) 123 Settings Section 124 Springs 131 Detectable object 132 Sensor (Photoreflector) 133 Settings Section 141 Detectable object 142 Sensor (Photoreflector) 143 Settings Section

Claims

1. A detection target is installed on one of the following: a drive target configured to be slidable or rotatable, and a housing to which the drive target is attached. A sensor installed on the other side of the object to be driven and the housing, capable of detecting the object to be detected, A setting unit sets a reference position on the housing of the object to be driven according to the detection status of the object to be detected by the sensor, A calibration device equipped with, The setting unit, by sliding or rotating the object to be driven in a first direction at a first speed, detects one of the transitions of the object to be detected by the sensor, from detection to non-detection, or from non-detection to detection, by sliding or rotating the object in a second direction opposite to the first direction at a second speed slower than the first speed, detects the other transition of the object to be detected by the sensor, from detection to non-detection, or from non-detection to detection, and sets the position of the object to be driven at the timing when the other transition is detected as the reference position. A calibration device, The object to be detected is a mechanical stopper, The aforementioned sensor is A pressure sensor that detects whether or not it has come into contact with the mechanical stopper, The pressure sensor has a spring that absorbs the impact when it comes into contact with the mechanical stopper. Calibration device.

2. The calibration device according to claim 1, The object to be driven and, The casing and A transport robot equipped with [a specific feature / equipment].

3. The drive unit further comprises a drive unit for driving the object to be driven, The calibration device sets the reference position of the driven object by sliding or rotating the driven object in the drive unit. The transport robot according to claim 2.

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