JP2014065098A - Robot device, orbit simulation device for articulated robot and orbit creation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot device, an orbit simulation device for an articulated robot, and an orbit creation method capable of easily creating an orbit for avoiding an obstacle, on the basis of instruction points.SOLUTION: The robot device includes: an articulated robot 2; a force sensor 23 capable of detecting reaction force applied on the articulated robot 2 when the articulated robot comes in contact with an obstacle 100; and a controller 6 for, when a movement start point where a tip part of the articulated robot 2 starts moving and a movement end point where the tip part finishes moving are inputted, calculating an interpolated orbit 103 on the basis of the movement start point and the movement end point, and when the articulated robot 2 is driven along the interpolated orbit 103, and the articulated robot 2 comes into contact with the obstacle 100 and the force sensor 23 detects the reaction force from the obstacle 100, calculating a movement amount by which the articulated robot 2 is alienated in a direction crossing the interpolated orbit 103, on the basis of the reaction force, moving the articulated robot 2 by the movement amount, storing the movement amount, and creating an obstacle avoidance orbit 104 by adding the stored movement amount to the interpolated orbit 103.

Description

  The present invention relates to a robot apparatus that generates a trajectory from a teaching point, a trajectory simulation apparatus for an articulated robot, and a trajectory generation method, and in particular, a robot apparatus that can generate a trajectory that avoids an obstacle, a trajectory simulation apparatus for an articulated robot, and a trajectory. It relates to a generation method.

  In general, when generating the trajectory of an articulated robot, if the position and orientation at which work is started by the articulated robot and the position and orientation at which work is finished are input, the control device performs linear interpolation, interpolation of each axis angle, etc. This generates a trajectory from the start posture to the end posture.

  Further, when there is an obstacle on the generated trajectory, interference with the obstacle is expected, so the user adds a teaching point by dividing the trajectory in advance to avoid interference with the obstacle. Similarly, when the surrounding environment of an articulated robot that has already been taught a trajectory changes and the articulated robot interferes with the surrounding environment at any point in the trajectory, the user adds a teaching point that indicates the relay posture. Or make corrections to avoid interference with the surrounding environment. As described above, in the generation of the trajectory of the articulated robot, it is necessary to add or correct the teaching point of the relay posture in consideration of the interference between the articulated robot and the surrounding environment and the movable region of the articulated robot.

  Here, in order to consider interference with obstacles when adding and correcting the teaching point of the relay posture in the trajectory generation of the articulated robot, not only the end effector of the articulated robot but also all of the robot arm The link needs to be checked for interference with obstacles. Further, in order to perform a smooth posture change on the trajectory, it is necessary to determine the corrected teaching point so that the posture does not change extremely before and after the teaching point to be added or corrected.

  However, it takes teacher's skill and a lot of work time to know what posture the articulated robot can take and what kind of posture change is required to shift to that posture. There is a problem that it takes time and effort to add and correct teaching points.

  In response to this, as a trajectory generation method for an articulated robot that searches for a relay posture from a work start position to an end position, trajectory generation of a robot apparatus using a potential field is disclosed (see Patent Document 1).

  In the method described in Patent Document 1, a potential map in which a potential value whose level decreases as the distance from an obstacle is set is generated in advance. Then, by generating a path in the direction in which the evaluation function based on the movement distance from the start point, the movement distance to the target, and the potential map is the best, a trajectory that moves to the target point while avoiding the obstacle is generated. .

Japanese Patent Laid-Open No. 05-228860

  However, the method described in Patent Document 1 has a problem in that it requires a large calculation step of generating a potential map in advance, and when the obstacle moves, it cannot cope with the moving obstacle. .

  Accordingly, an object of the present invention is to provide a robot apparatus that can easily generate a trajectory that avoids an obstacle, a trajectory simulation apparatus for a multi-joint robot, and a trajectory generation method based on given teaching points.

  The present invention relates to a robot apparatus, a multi-joint robot, a detection sensor capable of detecting a reaction force from the obstacle acting on the multi-joint robot when the multi-joint robot contacts the obstacle, and the multi-joint When a movement start point at which the tip of the robot starts moving and a movement end point at which the tip ends moving are input, the tip is moved from the movement start point and the movement end point. An initial trajectory is calculated, and when the articulated robot is driven and controlled along the calculated initial trajectory, the detection sensor detects a reaction force from the obstacle when the articulated robot comes into contact with the obstacle. Then, a movement amount for moving the articulated robot in a direction intersecting the initial trajectory is calculated from the detected reaction force, the articulated robot is detoured by the movement amount, and the movement amount Stored advance, characterized in that the movement amount stored and a control device for generating an obstacle avoidance path in addition to the initial path.

  Further, the present invention provides a trajectory simulation apparatus for an articulated robot, a virtual movement start point at which the tip of the virtual articulated robot in the virtual space starts moving, and a virtual movement end point at which the tip ends movement. When the virtual movement start point and the virtual movement end point are input, a virtual initial trajectory for moving the tip is calculated from the virtual movement start point and the virtual movement end point. When the virtual articulated robot is moved along the virtual initial trajectory, the virtual articulated robot acts on the virtual articulated robot by contacting a virtual obstacle in the virtual space. A virtual movement amount for moving the virtual articulated robot in a direction intersecting the virtual initial trajectory is calculated from the virtual reaction force from the virtual obstacle, and the calculated virtual movement amount is recorded. By, characterized in that the stored the virtual movement amount and an image processing apparatus for generating an obstacle avoidance trajectory of the articulated robot by adding the virtual initial path.

  Further, according to the present invention, in the trajectory generation method for the articulated robot, the tip moves from a movement start point at which the tip of the articulated robot starts to move and a movement end point at which the tip ends movement. An initial trajectory generating step for generating an initial trajectory, a drive starting step for starting drive control of the articulated robot based on the generated initial trajectory, and the articulated robot moving based on the initial trajectory being in trouble When a detection sensor capable of detecting a reaction force from the obstacle acting on the articulated robot by detecting contact with an object detects the reaction force, the detected reaction force crosses the initial trajectory in the direction crossing the initial trajectory. A movement amount calculation step for calculating a movement amount for moving the articulated robot, a detour movement step for detouring the articulated robot by the movement amount, and the movement amount in the detour movement step A moving amount storing step of storing, characterized in that the moving amount storing equipped with, and the obstacle avoidance path generating step of generating an obstacle avoidance path in addition to the initial path.

  According to the present invention, it is possible to provide a robot apparatus, a multi-joint robot trajectory simulation apparatus, and a trajectory generation method that can easily generate a trajectory that avoids an obstacle based on a given teaching point.

It is a mimetic diagram showing the whole robot apparatus structure concerning a 1st embodiment of the present invention. It is a block diagram of the control apparatus which controls the articulated robot which concerns on 1st Embodiment. It is a flowchart which shows the track | orbit production | generation by the control apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows the obstruction avoidance track | orbit of the articulated robot which concerns on 1st Embodiment. It is a schematic diagram which shows the whole structure of the robot apparatus which concerns on 2nd Embodiment. It is a schematic diagram which shows the track | orbit simulation apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the track | orbit production | generation by the track | orbit simulation apparatus which concerns on 3rd Embodiment.

<First Embodiment>
Hereinafter, a robot apparatus 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. First, the overall configuration of the robot apparatus 1 according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing the overall structure of the robot apparatus 1 according to the first embodiment of the present invention. FIG. 2 is a block diagram of the control device 6 that controls the articulated robot 2 according to the first embodiment.

  As shown in FIG. 1, the robot apparatus 1 includes an articulated robot 2 and a control device 6 that controls the articulated robot 2.

  The articulated robot 2 includes a 6-axis articulated robot arm 20 and an end effector 21 connected to the tip of the robot arm 20. The robot arm 20 includes six actuators (not shown) that rotationally drive each joint around each joint axis. By selectively driving each of the six actuators, the end effector 21 can be moved to any 3 Move to dimension position. For example, the end effector is moved from the solid line position shown in FIG. 1 to the two-dot chain line position so as to pass through the complementary trajectory calculated by the control device 6 based on the teaching points (control start point and control end point) input by the user. 21 is moved.

  The end effector 21 includes a gripping claw 22 that grips a workpiece and the like, and a force sensor 23 as a detection sensor that can detect a stress (reaction force) acting on the gripping claw 22. The force sensor 23 detects a triaxial force and a triaxial moment generated in the grip claw 22.

  As shown in FIG. 2, the control device 6 is configured by connecting a robot arm 20 and an end effector 21 to a computer main body having an arithmetic device 60 and a storage device 61 via a bus. In addition, an input device 62, a display 64, a recording media reading device 66, a communication device 67, and the like are connected to the computer main body via a bus. In FIG. 2, an interface for connecting them is not shown.

  The arithmetic device 60 includes a CPU 60a and an image processing device 60b. The CPU 60a includes a robot control unit 60e.

  The robot control unit 60e drives and controls the robot arm 20 and the end effector 21 based on various programs stored in the storage device 61, settings input from the input device 62, and the like. For example, in the robot control unit 60e, the end effector 21 moves on the obstacle avoidance trajectory 104 (see FIG. 4 described later) for avoiding the obstacle 100 by impedance control based on the trajectory information described later stored in the storage device 61. The robot arm 20 is driven and controlled as described above.

  A detailed description of the drive control of the end effector 21 is omitted. The trajectory generation method of the articulated robot 2 will be described in detail later.

  The image processing device 60b controls the display 64 in accordance with a drawing instruction from the CPU 60a to display a predetermined image on the screen. The storage device 61 is connected to the CPU 60a via a bus, and is secured as a work area for the ROM 61a storing trajectory information such as control start points and control end points input by various programs, users, and the like, and the CPU 60a. RAM 61b.

  The input device 62 includes a keyboard 62a and a mouse 62b, and enables input of trajectory information such as a control start point and a control end point for moving the end effector 21, or other instructions. The recording medium reading device 66 is used for reading a computer-readable recording medium 68 in which various programs such as a trajectory generating program are recorded and storing it in the ROM 61a. The communication device 67 is used, for example, when downloading an update program or the like distributed from the Internet or the like via the communication device 67 without using the recording medium 68 as described above.

  Next, a method for generating the trajectory of the articulated robot 2 by the control device 6 of the robot apparatus 1 configured as described above will be described with reference to FIGS. FIG. 3 is a flowchart showing the trajectory generation of the articulated robot 2 by the control device 6 according to the first embodiment. FIG. 4 is a schematic diagram showing the obstacle avoidance trajectory 104 of the articulated robot 2 according to the first embodiment.

  As shown in FIG. 3, the trajectory generation method of the articulated robot 2 is divided into a preprocessing stage in which information is input by a user or the like and a control stage in which a final trajectory is calculated by the control device 6. can do. As a method for generating the trajectory of the multi-joint robot 2, first, information is input by the user in the preprocessing stage, and then the control stage by the control device 6 is executed. Each process in the control stage is stored in the ROM 61a of the control device 6 as a trajectory generation program and can be updated by, for example, an update program distributed from the Internet or the like via the communication device 67.

  Hereinafter, the trajectory generation method of the articulated robot 2 will be described separately in the preprocessing stage and the control stage.

  First, the preprocessing stage will be described. As a pre-processing stage, first, the user inputs a control start point as a movement start point and a control end point as a movement end point of the target articulated robot 2 by using the input device 62 and is input. The control start point and the control end point are stored in the ROM 61a (step S110). Note that the control start point and control end point input by the user are set in a movable region in a three-dimensional space in which the articulated robot 2 is movable.

  When the control start point and the control end point are stored in the ROM 61a, the control device 6 then uses the general complementing method to connect the control start point and the control end point as a complementary trajectory 103 ( 1 is generated (initial trajectory generation step). The generated complementary trajectory 103 is stored in the ROM 61a (step S120). In addition, the general complement method here is straight line complement that calculates the angle value of each axis at each point on the straight line when connecting from the control start point to the control end point with a straight line, or from the control start point This refers to joint complementation in which the difference between the angle values of each axis at the control end point is divided into arbitrary intervals. Further, the initial trajectory generation step may be stored in the ROM 61a of the control device 6 together with the control stage as part of the trajectory generation program.

  When the complementary trajectory 103 is generated, next, the obstacle 100 representing the inaccessible area is set on the three-dimensional space where the articulated robot 2 exists (step S130). It is possible to install a plurality of obstacles 100, and it is also possible to set a change in position according to time and a change in shape due to time. The preprocessing stage is completed by installing the obstacle 100.

  Next, the control stage will be described. When the control stage is executed by the control device 6, the articulated robot 2 is driven and controlled, and the end effector 21 is first moved along the complementary trajectory 103 (drive start process, step S140). At this time, the control device 6 receives the detection value detected by the force sensor 23, and the end effector 21 contacts (interferences) the obstacle 100 when the detection value exceeds a predetermined threshold value set in advance. It is determined that it has been (YES in step S150). That is, a reaction force when the detection value exceeds a predetermined threshold value set in advance is detected as a reaction force when the end effector 21 contacts the obstacle 100.

  Next, the control device 6 performs impedance control using the detection value of the force sensor 23, and the amount of movement in the direction intersecting the complementary trajectory 103 (direction orthogonal in the present embodiment) by impedance control. Is calculated (movement amount calculation step, step S160). The amount of movement is calculated by performing impedance control using “output amount”, “time derivative of output amount”, and “twice derivative of output amount” of the output of the force sensor 23 converted into the cross direction component. Is done. The direction intersecting the complementary trajectory 103 is not limited to the direction orthogonal (90 degrees) to the complementary trajectory 103, but a direction orthogonal is preferable.

  When the movement amount is calculated, the end effector 21 is detoured along the supplementary trajectory 103 to which the movement amount is added (detour movement step), and the movement amount at this time is stored (movement amount storage step). The control device 6 repeats the above while returning to step S140 until it determines that the end effector 21 is no longer in contact with the obstacle 100, and stores the respective movement amounts.

  On the other hand, if it is determined that the end effector 21 is no longer in contact with the obstacle 100 (NO in step S150), the control device 6 then determines whether or not the end effector 21 is displaced from the complementary track 103 with respect to the complementary track 103 ( Step S170). This is because, as a result of impedance control using the detection value from the force sensor 23, there may be a deviation amount in the cross direction between the position of the end effector 21 and the complementary trajectory 103. This is because the end point is not reached.

  The movement amount (correction amount) with respect to the trajectory detoured from the complementary trajectory 103 is calculated by performing impedance control using “deviation amount”, “derivation of deviation amount”, and “differential deviation amount twice” ( Step S180). Further, the direction intersecting with the complementary trajectory 103 is preferably a direction orthogonal to the complementary trajectory 103 (90 degrees), and the amount of deviation is calculated to be small.

  When the movement amount (correction amount) is calculated, when the end effector 21 is detoured to a position obtained by subtracting the movement amount (correction amount) from the movement amount in step S160, and the object 100 comes into contact with the obstacle 100 due to the movement. Repeats step S160 and stores the amount of movement at this time. By repeatedly performing such an operation, the end effector 21 moves toward the control end point while avoiding the obstacle 100.

  When the control end point is reached by repeating the above (step S190), the control result trajectory (stored movement amount) is stored in the ROM 61a as the obstacle avoidance trajectory 104 shown in FIG. Avoidance trajectory generation step, step S1100). On the other hand, if the control end point has not been reached, the process returns to step S140 and the above is repeated.

  As described above, the robot apparatus 1 according to the first embodiment generates the supplementary trajectory 103 only by giving the control start point and the control end point, and when there is an obstacle 100, the robot apparatus 1 automatically fails. An obstacle avoidance trajectory 104 for the object 100 is generated. Therefore, for example, a trajectory that avoids the obstacle 100 can be easily generated without using a process with a large calculation amount such as creating a potential map.

  This embodiment is particularly effective when a new obstacle is installed after a detailed trajectory has already been set. For example, if an operation that passes through a certain range many times is taught and then a part of the certain range is made an entry prohibition region, a great deal of labor is required for re-teaching. However, by using this embodiment, obstacles are installed in the entry prohibition area, and the trajectory design by impedance control is performed, so that the trajectory in the irrelevant part is maintained and the obstacle avoidance trajectory is easily corrected. It becomes possible.

  In the first embodiment, the force sensor 23 is provided in the end effector 21 and the reaction force generated in the grip claw 22 is detected. However, for example, a force sensor is provided in each joint of the robot arm 20. There may be. For example, a force sensor may be provided at each joint of the robot arm to detect a reaction force obtained when the robot arm contacts an obstacle. In this case, the interference position between the robot arm and the obstacle needs to be the second and subsequent degrees of freedom counted from the base (base) of the robot arm.

  In the first embodiment, the movement amount is calculated using the output of the force sensor 23. For example, the movement amount is calculated using a difference in the output of the force sensor 23 when passing through the complementary trajectory. It may be a configuration.

Second Embodiment
Next, a robot apparatus 1A according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in that a torque sensor (detection sensor) is provided on the robot arm. Therefore, in the second embodiment, the difference from the first embodiment, that is, the trajectory generation method when using a torque sensor will be mainly described, and the same reference numerals are given to the same configurations as in the first embodiment. A description thereof will be omitted. FIG. 5 is a schematic diagram showing the overall structure of the robot apparatus 1A according to the second embodiment.

  As shown in FIG. 5, the robot apparatus 1A according to the second embodiment includes an articulated robot 2A and a control apparatus 6A. The articulated robot 2A includes a 6-axis articulated robot arm 20A, And an end effector 21. The robot arm 20A is provided with a torque sensor 24 at each joint, and can measure the torque generated at each joint. Since the basic configuration of the control device 6A is the same as that of the control device 6 according to the first embodiment (see FIG. 2), description thereof will be omitted assuming that FIG. 2 is used. Hereinafter, the trajectory generation method using the torque sensor 24 will be described with reference to FIG.

  The trajectory generation method by the robot apparatus 1A according to the second embodiment is different in step S150 and step S160 shown in FIG. Hereinafter, step S150 and step S160 will be described.

  In Step S150 of the second embodiment, when the difference between the output torque of each joint detected by the torque sensor 24 of each joint and the detected value exceeds the preset threshold value while the robot arm 20A is moving, the obstacle 200 It determines with having contacted (YES of step S150). That is, the external force torque when the difference amount exceeds a predetermined threshold value set in advance is detected as the external force torque when the robot arm 20 </ b> A contacts the obstacle 200.

  If it is determined that the robot arm 20A has touched the obstacle 200, the control device 6A next detects the output torque of the torque sensor 24 measured when moving the initial movement and the detected value when the robot arm 20A touches the obstacle 200. Impedance control using the difference between and. Specifically, impedance control is performed using the “difference amount”, “differentiation of the difference amount”, and “double differentiation of the difference amount” between the output torque of each joint and the detection value, and the detection value becomes the output torque. The amount of differential torque that fits is derived. Then, it is added to the motor output when the end effector 21 moves along the complementary track 203.

  On the other hand, if it is determined that the robot arm 20A is no longer in contact with the obstacle 200 (NO in step S150), the control device 6A determines whether or not there is a deviation from the complementary track 203 of the end effector 21 with respect to the complementary track 103 as in the first embodiment. (Step S170). If there is a deviation amount, the movement amount (correction amount) is calculated so that the deviation amount is small as in the first embodiment.

  When the movement amount (correction amount) is calculated, when the end effector 21 is detoured to a position obtained by subtracting the movement amount (correction amount) from the movement amount in step S160, and the object 200 comes into contact with the obstacle 200 due to the movement. Repeats step S160 and stores the amount of movement at this time. As a result, as shown in FIG. 5, the complementary trajectory 203 is corrected to the obstacle avoidance trajectory 204, and the robot arm 20 </ b> A can pass through the trajectory 205 that can avoid the obstacle 200.

  The movement amount resulting from the addition to the motor output is stored as appropriate in the CPU 61a. When the control end point is reached, the control result trajectory is used as the obstacle avoidance trajectory 204 together with the movement amount obtained by adding the deviation amount in step S180. Stored in the ROM 61a.

  As described above, in the robot apparatus 1A according to the second embodiment, by providing the torque sensor 24 in the robot arm 20A, in addition to the effects according to the first embodiment, the trajectory generation considering the trajectory of the robot arm 20A can be performed. This makes it possible to generate a more accurate trajectory.

  In the second embodiment, the movement amount is calculated using the difference between the outputs of the torque sensor 24. However, for example, the movement amount may be calculated using only the output of the torque sensor 24.

<Third Embodiment>
Next, a trajectory simulation apparatus 7 for an articulated robot according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic diagram showing a trajectory simulation apparatus 7 according to the third embodiment.

  The trajectory simulation device 7 includes an input device 72 that can input various types of information and a control device 74 that simulates the trajectory based on the input information. The input device 72 includes a keyboard and a mouse (not shown), and trajectory information such as a virtual control start point as a virtual movement start point for moving the virtual articulated robot and a virtual control end point as a virtual movement end point, It is possible to input virtual obstacle information and other instructions.

  The control device 74 includes an image processing device 70b, a CPU 70a, and a ROM 71a. The image processing device 70b controls the display in accordance with a drawing instruction from the CPU 70a to display a predetermined image on the screen. The CPU 70a moves the virtual articulated robot on the display (in the virtual space) according to various programs stored in the ROM 71a, settings input from the input device 72, and the like. The ROM 71a also stores information I101 representing a physical quantity, a physical calculation method I102, and a control method I103.

  In the information I101 representing the physical quantity, physical quantities such as the shape of the virtual part constituting the virtual multi-joint robot to be simulated, the placement information in each joint and virtual space, the virtual sensor placement information, the shape and placement information of the virtual obstacle, and the like are included. Stored. The physical calculation method I102 includes a method of calculating the motion of each joint and simulating the motion of a virtual articulated robot, a method of simulating a virtual reaction force from a virtual obstacle by contacting the virtual obstacle, etc. Is stored. The control method I103 stores a method for complementing the virtual control end point from the virtual control start point, an impedance control method, and the like.

  Next, a method for generating the obstacle avoidance trajectory of the virtual articulated robot by the trajectory simulation device 7 configured as described above will be described with reference to FIG. FIG. 7 is a flowchart showing trajectory generation by the trajectory simulation apparatus 7 according to the third embodiment.

  First, the virtual control start point and virtual control end point of the target virtual multi-joint robot are input using the input device 72, and the input virtual control start point and virtual control end point are stored in the ROM 71a ( Step S210). Note that the virtual control start point and the virtual control end point input by the user are set in a movable area on a virtual space in which the virtual articulated robot can move.

  Next, the CPU 70a generates a virtual complementary trajectory as a virtual initial trajectory obtained by connecting the virtual control start point and the virtual control end point using a general complement method. The generated virtual complementary trajectory is stored in the ROM 71a (step S220). General interpolation methods include straight line interpolation that calculates the angle value of each axis at each point on the virtual line when the virtual control start point to the virtual control end point are connected by a straight line, and the virtual control start point From joint complementation, etc., in which the difference in angle value of each axis at the virtual control end point is divided into arbitrary intervals.

  Next, a virtual obstacle representing an inaccessible area is placed on the virtual space where the virtual articulated robot exists (step S230), and the virtual articulated robot is driven and controlled so that the tip of the virtual articulated robot is virtualized. Move along the complementary trajectory (step S240). At this time, the CPU 70a receives the detection value of the virtual force sensor, and if the detection value exceeds a predetermined threshold value, the virtual articulated robot has contacted (interfered) with the virtual obstacle. Judgment is made (YES in step S250). That is, the virtual reaction force when the detection value exceeds a predetermined threshold value set in advance is detected as a virtual detection value that would have touched the obstacle.

  Next, the CPU 70a performs impedance control using the virtual detection value of the virtual force sensor, and calculates a virtual movement amount with respect to the virtual complementary trajectory (step S260). In addition, since the calculation method of the virtual movement amount using impedance control is the same as that of 1st Embodiment, the description is abbreviate | omitted here. When the virtual movement amount is calculated, the tip of the virtual articulated robot is detoured along the virtual complementary trajectory to which the virtual movement amount is added, and the virtual movement amount at this time is stored. The CPU 70a repeats the above while returning to step S240 until it determines that the tip of the virtual articulated robot is no longer in contact with the virtual obstacle, and stores the respective virtual movement amounts.

  On the other hand, if it is determined that the tip of the virtual articulated robot is no longer in contact with the virtual obstacle (NO in step S250), the CPU 70a then shifts the tip of the virtual articulated robot relative to the virtual complementary trajectory with respect to the virtual complementary trajectory. Whether or not there is is determined (step S270). This is because, as a result of impedance control using the virtual detection value from the virtual force sensor, there may be a virtual deviation amount in the crossing direction between the position of the tip of the virtual articulated robot and the virtual complementary trajectory. is there. Note that the virtual correction amount (movement amount) for the virtual complementary trajectory is calculated by performing impedance control (step S280), but the calculation method is the same as that in the first embodiment, and thus the description thereof is omitted here. .

  When the virtual correction amount is calculated, when the tip of the virtual articulated robot is moved to the position obtained by subtracting the virtual correction amount from the virtual movement amount in step S260, and the virtual obstacle is in contact with the virtual obstacle, Step S260 is repeated, and the virtual movement amount at this time is stored. By repeating such an operation, the tip of the virtual articulated robot moves toward the virtual control end point while avoiding the virtual obstacle.

  By repeating the above, when reaching the virtual control end point (step S290), the virtual trajectory (stored virtual movement amount) of the control result is stored in the ROM 71a as the obstacle avoidance trajectory (step S2100). On the other hand, if the virtual control end point has not been reached, the process returns to step S240 and the above is repeated.

  As described above, since the trajectory generation is performed by the trajectory simulation device 7, the articulated robot and the obstacle are not damaged at the time of contact (interference) with the obstacle. Can be suppressed. For example, since an obstacle can be installed in the air, various modes of simulation can be performed at low cost.

  Also, for example, when there is a singular point where the articulated robot takes a unique posture within the movable range of the articulated robot, when teaching, the hand of the articulated robot is placed at the hand position of the articulated robot taking the unique posture. There are cases where you don't want to put it in. In such a case, a singular point can be set on the virtual space as a virtual obstacle.

  For example, a singular point can be set as a virtual obstacle by setting a spherical virtual obstacle centering on the hand of the virtual articulated robot when taking a singular posture. In this case, an omnidirectional virtual sensor is set at the center of the hand of the virtual articulated robot, and only the virtual sensor at the center of the hand is set to interfere with the virtual obstacle (in the simulation environment, only in an arbitrary part) It is possible to set a sensor that reacts). In this way, it is possible to output an operation (orbit) that avoids a singular point. In the simulation environment, it is possible to set a detection sensor that reacts only to an arbitrary part.

  Although the third embodiment has been described using a fixed virtual obstacle as the virtual obstacle, the virtual obstacle may be a movable virtual obstacle, for example. In this case, after setting the virtual obstacle, the virtual motion of the virtual obstacle in time series is stored in the CPU 70a, and the position of the virtual obstacle is updated in accordance with the movement of the virtual articulated robot. By doing in this way, a virtual obstacle can be made into a movable virtual obstacle, and it becomes possible to detect interference with a moving virtual obstacle.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above. In addition, the effects described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

  For example, although the present embodiment has been described using a multi-axis multi-joint robot arm having a plurality of rotation axes, the present invention is not limited to this. For example, a similar trajectory can be generated even when a multi-axis multi-joint robot arm having a linear motion axis is used.

1, 1A, 1B Robot device 2 Articulated robot 6 Control device (control unit)
7 Trajectory simulation device 20 Robot arm 21 End effector 23 Force sensor (detection sensor)
72 Input Device 74 Control Device 100 Obstacle 103 Complementary Trajectory (Initial Trajectory)
104 Obstacle avoidance trajectory 200 Obstacle

Claims (10)

With articulated robots,
A detection sensor capable of detecting a reaction force from the obstacle acting on the articulated robot when the articulated robot contacts the obstacle;
When a movement start point at which the tip of the articulated robot starts to move and a movement end point at which the tip ends moving, the tip from the movement start point and the movement end point are input. When the multi-joint robot is driven and controlled along the calculated initial trajectory, the multi-joint robot comes into contact with the obstacle, so that the detection sensor moves from the obstacle. When a force is detected, a movement amount for moving the articulated robot in a direction crossing the initial trajectory is calculated from the detected reaction force, the articulated robot is detoured by the movement amount, and the movement amount And a controller for generating an obstacle avoidance trajectory by adding the stored movement amount to the initial trajectory,
A robot apparatus characterized by that. The control device calculates a movement amount that approaches the initial trajectory when the detection sensor does not detect the reaction force, stores the movement amount while detouring the articulated robot with the movement amount, Adding the stored movement amount to the initial trajectory to generate the obstacle avoidance trajectory;
The robot apparatus according to claim 1. The articulated robot has a robot arm and an end effector provided at a tip of the robot arm,
The detection sensor comprises a force sensor that detects a reaction force acting on the end effector,
The control device calculates the movement amount by impedance control using a detection value of the reaction force detected by the force sensor;
The robot apparatus according to claim 1 or 2, wherein The detection sensor comprises a torque sensor that measures torque generated at each joint of the articulated robot,
The control device calculates the movement amount by impedance control using a difference amount between an output torque when moving on an initial trajectory and a detection value detected by the torque sensor when contacting the obstacle. ,
The robot apparatus according to any one of claims 1 to 3, wherein An input device capable of inputting a virtual movement start point at which the tip of the virtual articulated robot on the virtual space starts moving and a virtual movement end point at which the tip ends moving;
When the virtual movement start point and the virtual movement end point are input, a virtual initial trajectory for moving the tip from the virtual movement start point and the virtual movement end point is calculated, and along the virtual initial trajectory When the virtual articulated robot is moved, the virtual articulated robot will act on the virtual articulated robot by contacting the virtual obstacle in the virtual space. From the force, a virtual movement amount for moving the virtual articulated robot in a direction intersecting the virtual initial trajectory is calculated, the calculated virtual movement amount is stored, and the stored virtual movement amount is used as the virtual initial trajectory. And an image processing device that generates an obstacle avoidance trajectory of the articulated robot,
A trajectory simulation apparatus for an articulated robot. When the virtual articulated robot does not contact a virtual obstacle in the virtual space, the image processing apparatus calculates the virtual movement amount that approaches the virtual initial trajectory, and stores the virtual movement amount at that time Generating the obstacle avoidance trajectory in addition to the virtual initial trajectory,
The trajectory simulation apparatus for an articulated robot according to claim 5. An initial trajectory generating step for generating an initial trajectory for moving the tip from a movement start point at which the tip of the articulated robot starts moving, and a movement end point at which the tip ends moving;
A drive start step for starting drive control of the articulated robot based on the generated initial trajectory;
When the articulated robot that moves based on the initial trajectory comes into contact with an obstacle, a detection sensor that can detect a reaction force from the obstacle acting on the articulated robot detects the reaction force. A movement amount calculating step of calculating a movement amount for moving the articulated robot in a direction intersecting the initial trajectory from the reaction force,
A detour movement step of detouring the articulated robot by the amount of movement;
A movement amount storage step for storing the movement amount in the detour movement step;
An obstacle avoidance trajectory generating step of generating an obstacle avoidance trajectory by adding the stored movement amount to the initial trajectory,
A trajectory generation method for an articulated robot. The movement amount calculating step calculates the movement amount so as to approach the initial trajectory when the detection sensor does not detect the reaction force.
The trajectory generation method for an articulated robot according to claim 7.   A trajectory generation program for an articulated robot for causing a computer to execute each step according to claim 7 or 8.   A computer-readable recording medium in which the trajectory generation program for the articulated robot according to claim 9 is recorded.

Images