JP2016078185A - robot - Google Patents

Abstract

An object of the present invention is to provide a robot that can operate a target object with high precision. A robot 1 includes a cart 10, an arm 12 provided directly or indirectly on the cart 10, a hand 13 provided on the arm 12 and grasping at least a part of an object, and a hand 13 in a detection area. It has a distance sensor 14 that detects distance information to an object, and a control device 15. The control device 15 performs a first operation of moving the arm 12 while being gripped by the hand 13, and an operation after the first operation, and moves the cart 10 so that the object gripped by the hand 13 moves. and the second operation. Further, the control device 15 acquires the positional relationship between the object and the trolley 10 based on the distance information in the first operation, and controls the movement of the trolley 10 to maintain the positional relationship during the second operation. [Selection diagram] Figure 5

Description

  The present invention relates to a robot, and more particularly to a robot that moves an object.

  2. Description of the Related Art In recent years, life support robots (HSR: Human Support Robot) and the like are required to operate objects such as furniture. In such a robot, a technique is known in which the distance to an object is measured using a distance sensor, and the self-position is estimated based on the measurement result.

  For example, Patent Document 1 discloses a technique for estimating a self-position by geometrically matching a measurement result obtained by a sensor that measures a distance to an object existing around a robot with an environment map.

JP 2012-93811 A

  For example, in the case of furniture operations such as opening a drawer, the amount of movement of an object is insufficient only by movement of a robot arm, and thus movement of a carriage is required. The movement of the carriage estimates its own position by a distance sensor, but the detection range of the distance sensor includes objects whose positions have been fluctuated by operation, and the accuracy of self-position estimation is not sufficient, for example When the cart slips, there is a problem that it is difficult to accurately operate the object.

  The present invention has been made against the background described above, and an object thereof is to provide a robot capable of operating a target object with high accuracy.

  The robot according to the present invention includes a carriage, an arm provided directly or indirectly on the carriage, a grip provided on the arm and gripping at least a part of an object, and an object in a detection region. A distance detecting means for detecting distance information; a first operation for moving the arm in a state of being gripped by the gripping portion; and an operation after the first motion, the target being gripped by the gripping portion Control means for controlling the second operation of moving the carriage so that the vehicle moves, and the control means uses the first action to determine the positional relationship between the object and the carriage based on the distance information. And the movement of the carriage is controlled so as to maintain the positional relationship during the second operation.

  According to such a robot, the position of the carriage is controlled so as to maintain the positional relation even when the positional relation between the carriage and the object is shifted while the carriage is moving while holding the object. Is done. Therefore, for example, even when the carriage slips during the second operation, the position of the carriage can be corrected and the carriage can be controlled with high accuracy in the robot in a state where the object is gripped. For this reason, the robot can operate the object with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the robot which can operate a target object with a sufficient precision can be provided.

It is a perspective view which shows the external appearance of the robot which concerns on embodiment. It is a top view explaining control of a trolley. (A) shows the state of detection by the position and distance sensor of the carriage at time t, (b) shows the state of detection by the position and distance sensor of the carriage at time t + 1, and (c) A state of matching between the detection result at t and the detection result at time t + 1 is shown. It is a block diagram which shows an example of a function structure of the control apparatus which concerns on embodiment. It is a schematic diagram explaining the tracking of the operation target using a distance sensor, (a) shows a state after the first operation and before the second operation, and (b) during the second operation. It shows a state. It is a flowchart which shows an example of operation | movement of the control apparatus which concerns on embodiment. It is a schematic diagram which shows a mode that operation which the robot pulls out drawer | drawer was seen from the top, (a) shows the mode before 1st operation | movement, (b) is after 1st operation | movement and before 2nd operation | movement. (C) shows a state during the second operation. It is a schematic diagram explaining operation which a robot opens a door. It is a schematic diagram which shows a mode that the obstruction invaded when the robot is performing operation which opens a door.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing an appearance of a robot 1 according to the embodiment. The robot 1 includes a carriage 10, a robot body 11, an arm 12, a hand 13, a distance sensor 14, and a control device 15.

  For example, the cart 10 is provided with a caster (not shown) and a pair of opposed driving wheels (not shown), and moves according to a control signal. Specifically, the carriage 10 moves when a carriage drive mechanism constituted by a motor or the like operates based on a control signal from the control device 15.

  In addition, for example, by detecting the rotation information of the driving wheel by a cart state detection sensor such as an encoder, the speed, moving direction, moving track, and the like of the cart 10 are detected. The detection result by the cart state detection sensor is output to the control device 15.

  The robot body 11 is installed on the carriage 10 and moves as the carriage 10 moves. The robot body 11 may be fixedly installed with respect to the carriage 10 or may be installed so as to be variable with respect to the carriage 10. For example, the robot body 11 may be installed so as to be able to turn on the carriage 10. In addition, a drive mechanism for changing the position and orientation of the robot body 11 itself may be provided.

  The arm 12 is directly or indirectly provided on the carriage 10 and is configured as an articulated arm, for example. The arm 12 is provided on the front surface of the robot body 11, for example. In the present embodiment, the arm 12 is supported by the robot body 11 and indirectly provided on the carriage 10, but the arm 12 may be provided directly on the carriage 10. The position and orientation of the arm 12 is changed by the operation of an arm driving mechanism including a motor or the like, for example. The arm drive mechanism operates in accordance with a control signal from the control device 15. With such a configuration, the arm 12 performs various operations such as rotation and refraction of the joint portion and expansion and contraction according to the control signal.

  Further, the arm 12 is provided with an arm state detection sensor that detects a state such as a posture and a position of the arm 12 by detecting rotation information of the joint portion by an encoder or the like, for example, and the detection result is output to the control device 15. Is done.

  The hand 13 (gripping part) is provided as an operating mechanism that is provided at, for example, the distal end of the arm 12 and grips at least a part of the operation target (grip target) (for example, a handle of the target). For example, the hand 13 operates an object such as furniture or joinery. The position and orientation of the hand 13 change due to the operation of a hand drive mechanism including a motor, for example. The hand drive mechanism operates in accordance with a control signal from the control device 15.

  Further, the hand 13 is provided with a hand state detection sensor that detects a state such as the posture and position of the hand 13 by detecting rotation information of the joint portion by an encoder or the like, for example, and the detection result is output to the control device 15. Is done.

  The distance sensor 14 corresponds to distance detection means, and detects distance information between the environment (object) in the detection region S around the robot 1 and the carriage 10. In FIG. 1, the detection area S is illustrated as a planar area, but the detection area S is not limited to two dimensions, and may be three dimensions. As the distance sensor 14, for example, a laser range finder is used. For example, the laser range finder radiates laser light radially to the detection area S in front of the robot 1 and detects the distance information of the object by receiving reflected light from the object in the detection area S. Can do. The distance sensor 14 is not limited to the laser range finder. For example, an arbitrary distance sensor such as a depth sensor, an ultrasonic sensor, an infrared sensor, or a camera can be used.

  The distance sensor 14 is arranged so that at least a part of the detection area S of the distance sensor 14 and the operation area of the hand 13 overlap. For example, the distance sensor 14 is provided at a position where the direction in which the arm 12 is attached can be detected on the outer periphery of the cart 10 or the robot body 11.

  The control device 15 (control means) is built in, for example, the robot body 11, but may be provided in other components such as the carriage 10. The control device 15 includes, for example, a CPU (Central Processing Unit) (not shown) that performs control processing, arithmetic processing, and the like, a ROM (Read Only Memory) and a RAM that store control programs, arithmetic programs, processing data, and the like executed by the CPU The hardware is configured around a microcomputer including a storage unit (not shown) composed of (Random Access Memory).

  The control device 15 includes instruction information (command value) including instructions such as operation work contents and movement contents, and detection results from the distance sensor 14, the above-described cart state detection sensor, arm state detection sensor, and hand state detection sensor. Based on the above, each of the above-described drive mechanisms is controlled, and the process shown in FIG.

  Here, control of movement of the carriage 10 will be described. In this embodiment, the cart 10 is controlled by position estimation (laser odometry) using a laser by the distance sensor 14. FIG. 2 is a plan view for explaining the control of the carriage 10. In FIG. 2, a solid line extending radially from the carriage 10 indicates measurement by the distance sensor 14. In FIG. 2, the thick line on the wall 2 indicates the shape obtained from the detection result by the distance sensor 14. FIG. 2A shows the position of the carriage 10 relative to the wall 2 and the state detected by the distance sensor 14 at time t. FIG. 2B shows the position of the carriage 10 relative to the wall 2 and the state detected by the distance sensor 14 at time t + 1. As shown in the figure, the carriage 10 moves so as to approach the wall 2 from time t to time t + 1. As shown in FIG. 2, the distance sensor 14 measures, for example, N points in the detection region S, and determines the shape of the environment (object) existing around from the detection result. As shown in FIG. 2C, the control device 15 determines the shape identified based on the detection result of the distance sensor 14 at time t and the shape identified based on the detection result of the distance sensor 14 at time t + 1. By matching, the self position of the robot 1 is estimated.

  As described above, since the surrounding shape of the robot 1 is used for the self-position estimation, it is assumed that the surrounding environment of the robot 1 does not move (is static) for accurate estimation of the self-position. It becomes. As shown in FIG. 2, when the robot 1 is not operating an object, the surrounding environment of the robot 1 is static, so that the carriage is slipped (for example, side slip or slipping due to idling of driving wheels). Even if it occurs, it can be expected that the position of the robot 1 (cart 10) is estimated by the above method. However, when the robot 1 is operating an object such as opening a door or opening a drawer, the distance sensor 14 detects the moving object, so that the matching shown in FIG. 2 is sufficiently performed. As a result, the self-position estimation accuracy deteriorates. For this reason, when the operation of the object is accompanied by the movement of the carriage 10, the position of the carriage 10 cannot be accurately controlled so as to follow the commanded trajectory, and the object cannot be accurately operated. Therefore, in the present embodiment, when the robot 1 operates the object, the accuracy of the operation of the object is improved by performing the following control. In this embodiment, when the robot 1 is moved by the carriage 10 without operating the object, the robot 1 is estimated and controlled by the above method shown in FIG. In addition, for the self-position estimation, map information represented about the environment in which the robot 1 operates may be used. For example, the control device 15 may use the matching between the detection result acquired by the detection by the distance sensor 14 and the map information for estimation of the self position, or other known self position estimation may be applied. .

  FIG. 3 is a block diagram illustrating an example of a part of the functional configuration of the control device 15 according to the embodiment. Each configuration illustrated in FIG. 3 may be realized, for example, by the CPU 15a executing the control program or the arithmetic program, or may be realized by hardware.

  The control device 15 includes a hand / arm control unit 151, a cart control unit 152, a positional relationship acquisition unit 153, and a positional relationship determination unit 154.

  The hand / arm control unit 151 controls the operation of the arm 12 and the hand 13 by sending control signals to the drive mechanisms of the arm 12 and the hand 13 so as to realize the operation according to the instruction information (command value). Here, in particular, when the hand / arm control unit 151 of the present embodiment grips the operation target with the hand 13, the hand 13 performs the first operation of moving the arm 12 while holding the operation target. Control. More specifically, the first operation is an operation of moving the position of the arm 12 so that the operation target moves by a predetermined amount of movement while the hand 13 holds the operation target. . In the first operation, the carriage 10 does not move and is stationary.

  The cart control unit 152 estimates the self-position using the detection result of the distance sensor 14 and sends a control signal to the drive mechanism of the cart 10 so as to realize the operation according to the instruction information (command value). Control the movement of. Here, the cart control unit 152 of the present embodiment controls to perform the second operation, particularly when the first operation described above is completed. Here, the second operation is an operation performed after the first operation, and specifically, the position of the operation target gripped by the hand 13 moves along the command information (command value). This is an operation of moving the position of the carriage 10. Further, during the second operation, the arm 12 and the hand 13 are not operated, and the relative positions of the arm 12 and the hand 13 with respect to the carriage 10 do not change.

  In addition, during the second operation, the cart control unit 152 controls the cart 10 so that the positional relationship between the cart 10 and the operation target object maintains the standard positional relationship according to the determination result by the positional relationship determination unit 154 described later. To do. Specifically, when the positional relationship determination unit 154 determines that the positional relationship between the cart 10 and the operation target is deviated from a reference positional relationship described later, the cart control unit 152 moves in a direction to eliminate the deviation. The movement of the carriage 10 is controlled so as to run or rotate.

  The positional relationship acquisition unit 153 acquires the positional relationship between the operation target and the carriage 10 based on the detection result (distance information) by the distance sensor 14. Here, the positional relationship acquisition unit 153 acquires a positional relationship (hereinafter referred to as a reference positional relationship) that serves as a reference between the operation target and the carriage 10 based on a detection result (distance information) by the distance sensor 14 by the first operation. To do. The positional relationship acquisition unit 153 acquires the reference positional relationship based on the measurement points where the variation occurred before and after the first operation from the detection results of the distance sensor 14 before and after the first operation. Specifically, for example, the positional relationship acquisition unit 153 first has N-point distance measurement data by the distance sensor 14 before the first operation and N-point distance measurement data by the distance sensor 14 after the first operation. And the measurement points where the distance measurement data fluctuates by a predetermined value or more are extracted from the N measurement points. Next, the positional relationship acquisition unit 153 stores shape data representing the shape obtained by connecting the extracted measurement points as reference positional relationship data, for example, in a storage unit provided in the control device 15. The reference position relationship data may further include distance measurement data indicating the distance of each extracted measurement point, or the reference position relationship data may be extracted instead of the shape data. Ranging data indicating the distance between points may be used.

  Further, the positional relationship acquisition unit 153 acquires the positional relationship between the operation target and the carriage 10 during the second operation. Here, a method for tracking the operation target in the second operation will be described. FIG. 4 is a schematic diagram illustrating the tracking of the operation target using the distance sensor 14. FIG. 4 shows a state in which the robot 1 sees the operation of pulling out the drawer 41 from the chase body 40 of the chance 4 from above. In the example shown in FIG. 4, the chase 4 is placed close to the wall 3 arranged in a U-shape. In the drawing, an arrow extending from the carriage 10 indicates N laser scans by the distance sensor 14. 4A shows a state after the first operation and before the second operation, and FIG. 4B shows a state during the second operation. In this example, it is assumed that the Lth to Mth laser scans of the N laser scans are scans for the drawer 41 that is the operation target. That is, it is assumed that the scan is a change in the detection result before and after the first operation. In this case, in the second operation, the positional relationship acquisition unit 153 tracks the position of the operation target by using the detection results for the L-th to M-th laser scans of the N laser scans, The positional relationship between the carriage 10 and the operation target is acquired. Thereby, for example, as shown in FIG. 4B, when the carriage 10 moving backward slides and tilts compared to before the second operation, the Lth to Mth lasers. Since the detection result of the scan changes from the detection result before the second operation (see FIG. 4A), the control device 15 can recognize this inclination.

  As described above, the positional relationship acquisition unit 153 determines the measurement points corresponding to the measurement points extracted when acquiring the reference positional relationship (coordinates specified by the detection results of the Lth to Mth laser scans in FIG. 4). Point) is extracted, and for example, shape data representing a shape obtained by connecting these measurement points is used as positional relationship data during the second operation. The positional relationship acquisition unit 153 may acquire the positional relationship for each predetermined time interval during the second operation, or may acquire the positional relationship for each predetermined movement distance.

  The positional relationship determination unit 154 compares the positional relationship data during the second operation with the reference positional relationship data, and determines whether the positional relationship data during the second operation is deviated from the reference positional relationship data. . Specifically, the positional relationship determination unit 154 matches both data and determines whether there is a difference exceeding a predetermined threshold. The predetermined threshold value may be zero. If the positional relationship determination unit 154 determines that the positional relationship during the second operation is deviated from the reference positional relationship, the positional relationship determination unit 154 notifies the cart control unit 152 of the positional relationship. For example, the positional relationship determination unit 154 notifies the carriage control unit 152 of a deviation amount such as a deviation direction and a distance, and the carriage control unit 152 responds to the carriage 10 to eliminate the notified deviation amount. Control to move.

  Next, an example of the above-described processing flow will be described with reference to FIGS. FIG. 5 is a flowchart showing an example of the operation of the control device 15 according to the present embodiment. FIG. 6 shows a state in which the robot 1 sees the operation of pulling out the drawer 41 from the chase body 40 of the chance 4 from the top, as in FIG. 6A shows the state before the first operation, FIG. 6B shows the state after the first operation and before the second operation, and FIG. 6C shows the state before the second operation. The state during operation is shown.

  First, in step 100 (S100), the hand 13 grasps an object as a premise of this processing (see FIG. 6A). For example, the cart control unit 152 controls the cart 10 to move in front of the dresser 4 that is the object based on the command information, and the hand arm control unit 151 controls the arm 12 and the hand 13 according to the instruction information. By controlling this operation, the hand 13 of the robot 1 holds the handle of the drawer 41. In addition, in the movement of the carriage 10 in front of the chance 4, for example, as shown in FIG. 2, the movement is performed by laser odometry using information on all measurement points of the distance sensor 14.

  In step 101 (S101), the hand / arm control unit 151 moves the position of the arm 12 so that the object moves by a predetermined amount of movement while the hand 13 is gripping the object (first operation). The operation is controlled (see FIG. 6B). In the first operation, the object is not moved by the movement of the carriage 10. For example, the hand arm control unit 151 pulls out the drawer 41 by X centimeters as a predetermined movement amount in a state where the handle of the drawer 41 is gripped by the hand 13.

  In step 102 (S102), the positional relationship acquisition unit 153 determines the measurement points where the detection result by the distance sensor 14 has changed before and after the movement of the arm 12 in step 101 (the portion surrounded by the broken line in FIG. 6B). See). If there is a measurement point where fluctuation has occurred (YES in step 103), the process proceeds to step 104. On the other hand, if there is no measurement point at which fluctuation has occurred (No in step 103), the process returns to step 101, and the movement by the arm 12 is attempted again.

  In step 104 (S104), the positional relationship acquisition unit 153 stores data of the reference positional relationship R that is the relationship between the object and the carriage 10. Specifically, for example, the positional relationship acquisition unit 153 stores the shape data of the object represented by the measurement point recognized in Step 101 in the storage unit as data of the reference positional relationship R.

  In step 105 (S105), the cart control unit 152 controls the movement (second operation) of the cart 10 so as to realize the operation according to the instruction information (command value) (see FIG. 6C). In the second operation, the object is not moved by the movement of the arm 12 and the hand 13.

  In step 106 (S106), the positional relationship acquisition unit 153 acquires the positional relationship between the object and the carriage 10. The positional relationship acquisition unit 153 acquires, for example, shape data representing the shape connecting the measurement points corresponding to the measurement points recognized when acquiring the reference positional relationship R as positional relationship data. Further, the positional relationship determination unit 154 matches the positional relationship acquired by the positional relationship acquisition unit 153 with the data of the reference positional relationship R stored in step 104, and exceeds a threshold value that is predetermined for the positional relationship. Determine if there is a difference. If there is a difference (No in Step 107), the process proceeds to Step 108. On the other hand, if there is no difference (Yes in Step 107), the process proceeds to Step 109.

  In step 108 (S108), the cart control unit 152 performs control to move the cart 10 so that the positional relationship between the object and the cart 10 approaches the reference positional relationship R. Specifically, for example, the cart control unit 152 controls the movement of the cart 10 so as to run or rotate in a direction to eliminate the deviation from the reference positional relationship R. After performing step 108, the process returns to step 106.

  In step 109 (S109), the carriage control unit 152 determines whether or not the target operation has been completed. Specifically, for example, the cart control unit 152 determines whether or not the operation instructed by the command information has been completed. If the operation has not been completed, the process returns to step 105. If the operation has been completed, the process ends.

  According to the robot 1 according to the present embodiment, even if the carriage slips while the carriage is moving while holding the object, for example, the slip is detected based on a difference from the reference positional relationship. And since the trolley | bogie 10 is controlled so that the positional relationship of the trolley | bogie 10 and a target object returns to reference | standard positional relationship, a trolley | bogie can be accurately controlled according to command information in the robot of the state which hold | gripped the target object. For this reason, the robot can operate the object with high accuracy. In addition, according to the present embodiment, it is possible to realize an operation with higher accuracy than the conventional one only by changing the logic without adding a device such as newly adding sensors.

  While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the operation of pulling the drawer 41 of the chase 4 has been described by way of example. However, the operation can be similarly applied even to the operation of putting the drawer 41 into the chase body 40. Moreover, it is not limited to the operation of the chase, but may be an operation of other furniture, joinery, or other objects.

  For example, the present invention may be applied to a door opening / closing operation. FIG. 7 is a schematic diagram illustrating an operation in which the robot 1 opens the door 5. Note that FIG. 7 illustrates a state in which the operation of the robot 1 opening the door 5 is viewed from above. As shown in FIG. 7, the cart 10 moves along the turning of the door 5 in order to maintain the reference positional relationship R during the second operation. Thus, by controlling the carriage 10 so as to maintain the reference positional relationship R, the door opening / closing operation can be realized with high accuracy.

  Moreover, the robot 1 may be provided with an abnormality detection function for detecting an obstacle when operating the object. For example, as illustrated in FIG. 8, the robot 1 may detect an obstacle 6 (for example, a person) when operating the door 5. Specifically, the robot 1 detects an obstacle as follows, for example. In FIG. 8, the solid line extending from the carriage 10 to the door 5 or the obstacle 6 indicates laser scanning by the distance sensor 14.

  As described above, since the movement of the carriage 10 is controlled so as to maintain the reference positional relationship, in the acquisition of the positional relationship that is sequentially performed during the second operation, substantially the same shape data is obtained. However, when the obstacle 6 enters the detection range of the distance sensor 14, data corresponding to the obstacle 6 appears in the distance measurement data of the distance sensor 14. For this reason, for example, when a measurement point closer to a predetermined threshold or more than a desired measurement distance (a distance in the reference position relationship) is detected, the positional relationship determination unit 154 causes the obstacle to enter the movement range of the target object. An abnormality may be detected as having entered. Moreover, when abnormality is detected, the robot 1 may perform alerting | reporting for alerting by speech, an alarm sound, a display, etc., and may stop operation | movement urgently.

DESCRIPTION OF SYMBOLS 1 Robot 10 Carriage 11 Robot main body 12 Arm 13 Hand 14 Distance sensor 15 Control apparatus 151 Hand arm control part 152 Carriage control part 153 Position relation acquisition part 154 Position relation determination part

Claims (1)

Cart,
An arm provided directly or indirectly on the carriage,
A grip portion provided on the arm and gripping at least a part of the object;
Distance detecting means for detecting distance information with an object in the detection region;
A first operation of moving the arm in a state of being gripped by the gripping portion, and an operation after the first motion, wherein the carriage moves the carriage so that the object gripped by the gripping portion moves. Control means for controlling the operation of
The control means acquires the positional relationship between the object and the cart based on the distance information by the first operation, and controls the movement of the cart so as to maintain the positional relationship during the second operation. Robot.

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