Hybrid Cable Drive With Magnetorheological Tension Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cable parallel robots face limitations due to ordinary direct current motors that cannot operate in reverse or locked-rotor modes for long periods, leading to heat issues and high costs, and torque motors have high inertia and volume, making them unsuitable for long-term cable tension control.
Innovation Solution
A distributed active/passive hybrid cable drive system incorporating a direct current motor, motor output gear, drive gear sets, and magnetorheological actuator modules, where the direct current motor powers the magnetorheological actuator modules to control cable tension, allowing for decoupling of rotation speed from torque and enabling forward and reverse cable pulling with adjustable damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ordinary direct current motors are used to drive cable parallel robots, then the system has low cost and simple structure, but the motors cannot operate in reverse or locked-rotor modes for long periods due to heat generation and coil burnout
Solution Approach 1:
The drive system is segmented into two functional parts: a simple direct current motor for power generation and a magnetorheological actuator module for torque control. This segmentation allows the motor to operate in optimal conditions while the magnetorheological component handles the demanding reverse and locked-rotor operations, resolving the contradiction between simplicity and reliability.
Solution Approach 2:
The magnetorheological actuator module serves as an intermediary between the direct current motor and the cable drive mechanism. It receives power from the motor and provides the necessary torque control with high reliability, protecting the motor from operating in damaging conditions while enabling long-term reliable operation.
2Force
If torque motors are used to control cable tension, then high torque and good control performance are achieved, but the motors have high cost, large volume, and high inertia
Solution Approach 1:
The traditional mechanical torque motor is replaced with a hybrid system combining a simple direct current motor and a magnetorheological actuator. The magnetorheological fluid provides variable damping characteristics that enable torque control without the bulk and inertia of conventional torque motors, achieving high torque with reduced volume.
Solution Approach 2:
The magnetorheological actuator changes its damping parameter in real-time to control torque output. By adjusting the magnetic field strength, the damping coefficient varies, enabling precise torque control comparable to torque motors but with significantly reduced volume and inertia.
3Reliability
If a hybrid drive system with magnetorheological actuators is implemented, then torque control performance and reliability are improved, but the system structure becomes more complex
Solution Approach 1:
The complex hybrid drive system is divided into modular magnetorheological actuator units, each independently connected to a direct current motor. This modular segmentation manages complexity by creating standardized, interchangeable modules that can be systematically assembled and maintained.
Solution Approach 2:
The magnetorheological actuator module serves multiple functions: it provides torque control, enables reverse operation, allows locked-rotor mode, and offers variable damping characteristics. This multi-functionality consolidates several requirements into a single component, managing overall system complexity while achieving diverse performance goals.
4Productivity
If the rotation speed of the direct current motor is increased to improve productivity, then power output increases, but torque control precision deteriorates due to coupling between speed and torque
Solution Approach 1:
The control function is segmented between the direct current motor (speed generation) and the magnetorheological actuator (torque control). This segmentation decouples speed and torque control, allowing the motor to operate at high speeds for productivity while the magnetorheological component independently maintains precise torque control.
Solution Approach 2:
The magnetorheological actuator acts as an intermediary that decouples the speed-torque coupling. It receives rotational energy from the high-speed motor and transforms it into precisely controlled torque output through variable damping, enabling high productivity without sacrificing torque control precision.
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
This system reduces costs, achieves high torque with low inertia, suppresses vibrations, and provides flexible, efficient cable control with reduced volume, improving force control performance and power efficiency compared to traditional systems.
Implementation Method 1
each magnetorheological actuator module includes a module frame, and a rotary magnetorheological actuator, an output reel, and a magnetorheological input gear that are installed in the module frame; the magnetorheological input gear is fixed on the rotary magnetorheological actuator and is capable of rotating around the module frame
Data Source
AI summary
The present invention discloses a distributed active/passive hybrid cable drive system, including a direct current motor, a magnetorheological actuator module, and a drive gear set. The direct current motor provides power for the system, the magnetorheological actuator adjusts output, a cable is driven to move by using a reel fixedly connected to an output shaft, the power is transmitted to a tail end by using the cable along a Bowden cable, and the tail end is connected to a controlled object, to implement control. The distributed active/passive hybrid cable drive system can implement controllable force output with large torque, small inertia, and high bandwidth, and has a small volume, high efficiency, and low costs compared with a pure motor drive system.