Multi-freedom-degree open loop stepping series mechanical arm and control method thereof

Abstract

The invention discloses a multi-freedom-degree open loop stepping series mechanical arm and a control method thereof. Under the power failure condition of the mechanical arm, the mechanical arm can naturally hang down; zero position finding devices are arranged on joints of the mechanical arm and are used for detecting mechanical zero positions of the joints of the mechanical arm; a camera with depth information is arranged in a mechanical arm motion space, and a cross target is arranged at the tail end of the mechanical arm; and the control method of the mechanical arm is further provided, after the mechanical arm is powered on, the mechanical arm is controlled to rotate to the posture approaching to the zero position, the zero finding action is executed, the joints are controlled to return to the zero position according to a certain sequence, the current joint positions are recorded as reference zero position accuracy, at the moment, the control position of the mechanical arm is notmatched with the actual position, and the control precision is ensured. According to the multi-freedom-degree open loop stepping series mechanical arm and the control method thereof, a position sensordoes not need to be added, zero finding is achieved during step out, and control precision of the multi-freedom-degree open loop stepping series mechanical arm is ensured.

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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