Cable System Reel Torque Control for Traveling Body
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Solution Overview
Problem
Existing cable systems for remote-controlled travelling bodies, especially in environments where radio waves are obstructed, face issues with cable slackening and tangling due to inertia and sudden attitude changes, leading to immobilization, and require complex control software to prevent erroneous reeling control.
Innovation Solution
A cable system with a reel device on the travelling body equipped with a rotation sensor, speed sensor, and motor controller that judges the reel's rotational direction and applies torque based on the sensors' information to manage cable unreeling and reeling, eliminating the need for accelerometers and complex software by comparing cable unreeling speed with travelling speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the motor is freed to allow smooth unreeling of the cable during forward movement, then the cable tension is reduced, but the cable becomes slackened when the travelling body suddenly stops due to inertia
Solution Approach 1:
The system uses a rotary encoder to detect the reel's rotation direction and speed, and a speed sensor to detect the traveling body's speed. The motor controller continuously compares the cable unreeling speed with the traveling speed and adjusts the motor torque accordingly. This feedback mechanism allows the system to respond dynamically to changes in motion state, preventing cable slackening when the traveling body stops suddenly while maintaining smooth unreeling during movement.
Solution Approach 2:
The motor controller dynamically adjusts the motor torque based on real-time comparison between cable unreeling speed and traveling speed. When the unreeling speed exceeds the traveling speed, the controller applies torque in the reeling direction to prevent excessive slack. This dynamic adjustment allows the system to adapt to changing conditions without requiring complex acceleration detection.
2Reliability
If an accelerometer is used to detect sudden stops and control cable reeling, then cable slackening is prevented, but the response speed is reduced due to noise and averaging requirements
Solution Approach 1:
The patent replaces the accelerometer-based detection system with a combination of rotary encoder and speed sensor. Instead of measuring acceleration directly (which requires noise filtering and averaging), the system compares the cable unreeling speed (from rotary encoder) with the traveling body speed (from speed sensor). This substitution eliminates the need for acceleration measurement and averaging, achieving faster response without compromising reliability.
3Reliability
If complex control software is added to prevent erroneous reeling control during vibrations or impacts, then false reeling is prevented, but the device complexity increases
Solution Approach 1:
The system uses continuous feedback from the rotary encoder and speed sensor to determine whether to apply motor torque. The motor controller compares cable unreeling speed with traveling speed and only applies torque when the unreeling speed exceeds the traveling speed. This simple feedback-based decision logic prevents false reeling during vibrations or impacts without requiring complex control software, as the physical comparison of speeds naturally filters out erroneous signals.
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 solution ensures stable travel by accurately controlling cable slack, increasing response speed, and preventing inadvertent reeling due to vibrations or impacts, reducing costs by eliminating the need for separate detectors and complex software.
Implementation Method 1
a rotary encoder for detecting rotation of the reel
Implementation Method 2
a speed sensor for outputting information about a travelling speed of the travelling body
Implementation Method 3
a motor for driving the reel
Data Source
AI summary
A cable system A includes a cable 3 for connecting a base device 1 and a travelling body 2, a reel device 10 mounted on the travelling body 2, a motor controller 40 for controlling a motor 15 of the reel device 10, and a rotary encoder 16 (rotation sensor) for detecting rotation of a reel 12. The motor controller 40 basically makes the motor 15 free, when the reel 12 is rotating in an unreeling direction, and basically applies a rotational torque in a reeling direction to the reel 12, when the reel 12 is rotating in the reeling direction. Furthermore, even if the reel 12 is rotating in the unreeling direction, if an unreeling speed of the cable 3 exceeds a travelling speed of the travelling body 2, the rotational torque in the reeling direction is applied to the reel 12. Slackening of the cable 3 is thereby prevented.