A multi-degree-of-freedom open-loop stepping series manipulator and its control method

Abstract

The invention discloses a multi-degree-of-freedom open-loop stepping series manipulator and a control method thereof. When the manipulator is powered off, the manipulator can droop naturally; each joint of the manipulator is equipped with a change finding device for detecting The mechanical zero position of each joint of the manipulator; a camera with depth information is installed in the movement space of the manipulator, and a cross target is installed at the end of the manipulator. The present invention further provides a control method for the mechanical arm. After the mechanical arm is powered on, the mechanical arm is controlled to rotate to a posture close to the zero position, and then the zero-finding action is performed, and each joint is controlled to return to zero in a certain order, and the current joints are recorded. The position is the exact value of the reference zero position. At this time, the control position of the mechanical arm is consistent with the actual position, and the control accuracy is guaranteed. The multi-degree-of-freedom open-loop stepping serial manipulator and the control method thereof of the present invention do not need to add position sensors, can realize change when out of step, and ensure the control accuracy of the multi-freedom open-loop stepping series manipulator.

Description

technical field [0001] The invention relates to a multi-degree-of-freedom open-loop stepping serial manipulator and a control method thereof, belonging to the fields of equipment automation and intelligent robots. Background technique [0002] Most of the existing traditional industrial manipulators use closed-loop servo drive. The advantages of servo drive are high precision, high energy efficiency, and good dynamic response, but the cost is also high, and due to the low torque and high speed characteristics of the servo motor, the manipulator The joint must adopt a harmonic reducer or RV reducer with a high reduction ratio, which further increases the cost pressure. [0003] In recent years, mechanical arm products used in service industry, entertainment demonstration, and teaching have appeared. Most of them adopt the step open-loop drive form. This drive form greatly reduces the cost and does not require position feedback devices. The speed and high torque characteristi...

AI Technical Summary

Problems solved by technology

The disadvantage of the zero-finding scheme of this open-loop motion system is that the zero position can only be located at the beginning or end of the motion stroke. For the robot joint, it can only rotate to the limit position, that is, the maximum or minimum angle within the joint rotation range. , to achieve change, which is impossible for many robot application scenarios. For example, if there are objects around, or the body is blocked, when a joint cannot move to the limit position, the robot will not be able to change the joint.

[0007] The existing position feedback schemes also include adding position sensors, such as photoelectric encoders, magnetoelectric encoders, resolvers, etc. These sensors are often expensive, bulky, heavy, and have many signal cables, which is not convenient for structure and electrical layout

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