Electric Actuator Control Modes for Pneumatic Cylinder Replacement
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Solution Overview
Problem
Existing electric actuators require different control methods when replacing pneumatic cylinders, necessitating specific programming and position detectors, making replacement cumbersome and inflexible.
Innovation Solution
An electric actuator with a control program and position detector compatible with fluid pressure cylinders, allowing for six modes corresponding to different electromagnetic valves, enabling seamless integration and control similar to pneumatic systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an electric actuator is used to replace a pneumatic cylinder, then energy efficiency is improved, but control compatibility deteriorates
Solution Approach 1:
The electric actuator is designed with multiple control modes including a pneumatic cylinder simulation mode that emulates the ON/OFF control behavior of pneumatic cylinders. This allows the same actuator to replace different types of pneumatic cylinders (single solenoid valve type, double solenoid valve types) while maintaining compatibility with existing control systems, thus achieving universality across multiple application scenarios.
Solution Approach 2:
The control unit changes operational parameters based on the selected control mode. In pneumatic cylinder simulation mode, the control parameters are adjusted to match the binary ON/OFF control characteristics of pneumatic systems, including setting acceleration and deceleration periods to ensure the actuator starts and stops similarly to pneumatic cylinders, thereby achieving parameter compatibility.
2Measurement precision
If conventional electric actuator control methods are used, then precise control is achieved, but operational complexity increases
Solution Approach 1:
The control unit dynamically adjusts operational parameters based on the selected control mode. When pneumatic cylinder simulation mode is selected, the system dynamically sets acceleration and deceleration periods to match pneumatic system behavior, allowing operators to switch between precise electric control and simplified pneumatic-like control without changing hardware or control programs.
3Loss of energy
If pneumatic cylinder replacement is implemented, then energy consumption is reduced, but system reconfiguration effort increases
Solution Approach 1:
The electric actuator maintains mechanical interface compatibility with pneumatic cylinders while providing multiple control modes. The output shaft, mounting structure, and dimensioning are designed to match pneumatic cylinder specifications, allowing direct physical replacement without system reconfiguration. The control unit includes pneumatic cylinder simulation mode that emulates existing control behavior, eliminating the need for control program modification.
4Adaptability or versatility
If multiple control modes are implemented, then adaptability is improved, but device complexity increases
Solution Approach 1:
Multiple control modes (pneumatic cylinder simulation mode with single solenoid valve type, double solenoid valve first type, double solenoid valve second type, and electric actuator mode) are merged into a single control unit. The control unit selects and executes the appropriate control algorithm based on the selected mode, consolidating what would otherwise require separate control circuits into one integrated system.
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 easy replacement and flexible control of electric actuators in automated machines by using the same control programs and position detectors as fluid pressure cylinders, improving operational efficiency and reducing complexity.
Implementation Method 1
a ball screw, which is a motion conversion mechanism, is provided in the electric actuator. The ball screw converts rotation of a rotary shaft of the motor to linear motion so as to move an output shaft in a linear direction.
Implementation Method 2
an electric motor is used in place of a pneumatic cylinder. Specifically, rotation of the electric motor is converted into a linear motion to cause an output shaft to reciprocate linearly.
Data Source
AI summary
An electric actuator includes a motion conversion mechanism and a position detector. The motion conversion mechanism converts rotation of a rotary shaft of a motor into linear motion of an output shaft. The position detector detects a permanent magnet M, which moves integrally with the output shaft. A motor control portion controls the motor based on commands from a host command unit. A control program for controlling the motor includes, as control modes, six fluid pressure cylinder modes, according to which the motor is controlled. Specifically, each of the control modes corresponds to one of the cases where the fluid pressure cylinder is controlled by three solenoid valves, or a two-position single solenoid valve, a two-position double solenoid valve, and a three-position double solenoid valve. The motor is controlled according to the selected control mode.