Linear Rotary Actuator Closed-Loop Control
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Solution Overview
Problem
Existing linear and rotary motors face issues with step-out, vibration, and difficulty in high-speed rotation due to open loop control, making precise control of rotation angles challenging.
Innovation Solution
A linear and rotary actuator system incorporating a shaft member with a hollow rotor, a rotary motor with a spline shaft and nut for linear movement, and an angle measuring unit for closed-loop control of the rotation angle, ensuring accurate and stable rotation and movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If open loop control is used in the rotary pulse motor, then the structure is simple, but step-out, vibration and difficulty in high-speed rotation occur
Solution Approach 1:
The patent introduces an angle measuring unit that detects the rotation angle of the rotor and feeds this information back to the rotary motor driver. The rotary motor driver adjusts the drive signals based on the feedback to ensure the rotor reaches the commanded angle, eliminating step-out and vibration while enabling stable high-speed rotation through closed-loop control.
2Adaptability or versatility
If a linear and rotary pulse motor is used, then linear and rotary movement can be achieved, but precise control of rotation angle is difficult due to open loop control
Solution Approach 1:
The angle measuring unit measures the actual rotation angle of the rotor and provides feedback to the rotary motor driver. This closed-loop control system continuously compares the actual angle with the commanded angle and adjusts the drive signals accordingly, achieving precise rotation angle control while maintaining the dual linear and rotary movement capabilities.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Facilitates precise control of the rotation angle of the shaft member, reducing vibration and enabling reliable high-speed operation by using closed-loop control and a spline nut mechanism for torque transmission and guidance.
Implementation Method 1
a rolling-element circulation passage including a loaded rolling-element rolling part facing the rolling-element rolling part of the spline shaft and a plurality of rolling elements arranged in the rolling-element circulation passage
Data Source
AI summary
A linear and rotary actuator system includes a shaft member moving linearly in an axial direction and rotating around an axis line, a hollow rotor surrounding the shaft member, a stator of a rotary motor having a space for holding the rotor and which rotates the rotor around the axis line, linear bearings, that rotates together with the rotor to transmit rotation of the rotor of the rotary motor to the shaft member and accepts linear movement of the shaft member, an angle measuring unit for measuring a rotation angle of the rotor, and a rotary motor driver for controlling the rotary motor in such a manner that the rotation angle of the rotor of the rotary motor measured by the angle measuring unit conforms to a command value. The rotation angle of the shaft member is controlled by controlling the rotation angle of the rotor of the rotary motor.