Patent ID: 12220814

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this disclosure are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.

FIG.1is a schematic system diagram illustrating a master-slave robot arm control system1according to an embodiment of the present disclosure. As shown inFIG.1, the master-slave robot arm control system1includes a master robot arm2, a slave robot arm3and a control unit4. The slave robot arm3is in communication with the master robot arm2, and the master robot arm2is configured to control the slave robot arm3. Therefore, the master robot arm2and the slave robot arm3are in tele-operation, and the slave robot arm3is controlled by the master robot arm2to perform remote tasks. In an embodiment, the movement trajectory of the slave robot arm3and the master robot arm2are synchronized, that is, the movement of the slave robot arm3is followed by the movement of the master robot arm2. The slave robot arm3generates and outputs a force feedback to the master robot arm2constantly, the force feedback reflects the forces received by the slave robot arm3during movement process. The control unit4is configured to control the master robot arm2and the slave robot arm3. When the control unit4executes a robot arm demonstration task, a user operates the master robot arm2to generate an action command according to a user command and the force feedback generated by the slave robot arm3. By executing the robot arm demonstration task through demonstration learning, learning from demonstration (LFD) is achieved. The action command corresponds to the movement trajectory of the master robot arm2. Since the slave robot arm3and the master robot arm2are synchronized, the movement trajectory of the slave robot arm3is the same as the movement trajectory of the master robot arm2during the robot arm demonstration task. In addition, during the movement process of the slave robot arm3, the slave robot arm3receives the forces and outputs the corresponding force feedback to the master robot arm2constantly, so the master robot arm2is aware of the force received by the slave robot arm3instantly. In an embodiment, the action command is generated through operating the grippers of the master robot arm2manually by the user. In an embodiment, the user command is instructed by the user.

The control unit4calculates and generates a movement command according to the action command and the force feedback. In an embodiment, the movement command includes a target coordinate. The control unit4controls the slave robot arm3to move according to the movement command and to generate a movement trajectory and the force feedback correspondingly. During the robot arm demonstration task, the slave robot arm3outputs the force feedback constantly, so the user may adjust the operation of the master robot arm2accordingly. For example, when the slave robot arm3encounters an obstacle during the movement process, the force feedback corresponding to encountered obstacle is generated and outputted to the master robot arm2, and the user can adjust the operation such as adjusting the trajectory of the master robot arm2manually so as to avoid the obstacle.

The control unit4executes the robot arm demonstration task for a plurality of times to collect a plurality of movement trajectories of the slave robot arm3. The control unit4utilizes a statistic module to analyze the plurality of movement trajectories and to generate an optimized trajectory of the slave robot arm3according to the analysis result. In an embodiment, the statistic module includes Gaussian mixture regression or Gaussian mixture model.

After the optimized trajectory of the slave robot arm3is obtained, the control unit4controls the slave robot arm3to execute a robot arm task according to the optimized trajectory. In an embodiment, the robot arm task is the same as robot arm demonstration task.

In the master-slave robot arm control system1of the present disclosure, the control system1controls the master and slave robot arms in tele-operation and takes the force feedback into consideration simultaneously. Since the force feedback is taken into consideration, the accuracy of the robot arm task is improved when the environment changes.

In an embodiment, an impedance control with the force feedback includes a gravity compensation value, wherein the gravity compensation value reflects the gravity force received by the slave robot arm3during movement process.

In an embodiment, the robot arm demonstration task includes at least one of picking a first compliant box, placing the first compliant box near a second compliant box, inserting the first compliant box into the second compliant box and retracting the first compliant box from the second compliant box. In an embodiment, while inserting the first compliant box into the second compliant box, the first compliant box is inserted into the second compliant box along an edge of the opening of the second compliant box, so as to improve the accuracy of inserting the first compliant box into the second compliant box.

In an embodiment, the position relationship between the first compliant box and the second compliant box is not limited. The robot arm demonstration tasks may be executed for a plurality of times with different position relationship between the first compliant box and the second compliant box. The plurality of movement trajectories of the slave robot arm3with different position relationship between the first compliant box and the second compliant box are obtained so as to generate a plurality of optimized trajectories corresponding to different position relationships respectively. The control unit4controls the slave robot arm3to execute a robot arm task according to the optimized trajectories. In an embodiment, the robot arm task is the same as one of the robot arm demonstration tasks.

FIG.2is a schematic flow chart illustrating a master-slave robot arm control method according to an embodiment of the present disclosure.FIG.3is a schematic flow chart illustrating the step S2of the master-slave robot arm control method ofFIG.2. The master-slave robot arm control method of the present disclosure is applicable for the master-slave robot arm control system1stated above. Please refer toFIGS.2and3, the master-slave robot arm control method of the present disclosure includes steps S1, S2, S3, S4, S5and S6. In the step S1, a master robot arm2and a slave robot arm3in communication with each other are provided, wherein the master robot arm2is configured to control the slave robot arm3. In the step S2, a robot arm demonstration task is executed, wherein the step S2includes steps S21, S22, S23, S24and S25. In the step S21, the slave robot arm3is utilized to generate and output a force feedback to the master robot arm2constantly, wherein the force feedback reflects the force received by the slave robot arm3during movement process. In the step S22, an action command is generated by operating the master robot arm2according to a user command and the force feedback. The master robot arm2can be operated by an user. In the step S23, a movement command is calculated and generated according to the action command and the force feedback. In the step S24, the slave robot arm3is controlled to move according to the movement command and to generate a movement trajectory and the force feedback correspondingly. In the step S25, the steps S21to S24are executed repeatedly until the robot arm demonstration task is finished. In the step S3, the step S2is performed repeatedly to collect a plurality of movement trajectories of the slave robot arm3. In the step S4, a statistic module is utilized to analyze the plurality of movement trajectories. In the step S5, an optimized trajectory of the slave robot arm3is generated according to the analysis result of the step S4. In the step S6, the slave robot arm3is controlled to execute a robot arm task according to the optimized trajectory.

In an embodiment, the robot arm demonstration task includes at least one of picking a first compliant box, placing the first compliant box near a second compliant box, inserting the first compliant box into the second compliant box and retracting the first compliant box from the second compliant box.

From the above descriptions, the present disclosure provides a master-slave robot arm control system and control method. The control system controls the master and slave robot arms in tele-operation and takes the force feedback into consideration simultaneously. Since the force feedback is taken into consideration, the accuracy of the robot arm task is improved when the environment changes.

While the disclosure has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.