Robot Arm Velocity Control to Prevent Mechanical Stopper Deformation
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Solution Overview
Problem
Conventional industrial robot control systems using mechanical stoppers limit the arm's operation range more narrowly than intended, leading to potential deformation and damage due to uncontrolled contact between mechanical stoppers.
Innovation Solution
An operation control system with a movable member, an actuator, and a control unit that recognizes the member's position and velocity, applying a constant resistance force to predict and prevent excessive contact forces by stopping the actuator when the member approaches the limit, thus preventing deformation and maximizing the movable range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a software limit is used to stop the arm before mechanical stopper contact, then deformation and damage are prevented, but the arm operation range becomes narrower than hardware limitation
Solution Approach 1:
The patent changes the control parameter from a simple position-based software limit to a two-dimensional coordinate system that includes both position and velocity. By monitoring velocity, the system can allow the arm to reach the mechanical stopper contact point while controlling the rate of contact to prevent damage, thus expanding the operation range while maintaining reliability.
Solution Approach 2:
The patent introduces dynamic velocity control alongside static position limits. The actuator control unit adjusts the velocity parameter based on the arm's position, allowing high-speed operation within safe margins and controlled deceleration near the mechanical stopper contact point. This dynamic approach maximizes the operation range while preventing deformation.
2Length of moving object
If no software limit is applied, then the arm operation range is maximized, but contact between mechanical stoppers causes deformation and damage
Solution Approach 1:
The patent implements a feedback mechanism where the operation state recognizing unit continuously monitors both position and velocity of the arm. This feedback information is fed to the actuator control unit, which adjusts the actuator operation in real-time. The velocity feedback allows the system to maintain full operation range while preventing excessive contact forces through active control.
Solution Approach 2:
The patent takes preliminary action by monitoring velocity before mechanical contact occurs. The actuator control unit uses velocity information to predict potential contact and initiates deceleration in advance, preventing excessive contact forces while allowing the arm to reach the full mechanical stopper contact point, thus maximizing operation range without damage.
3Productivity
If the actuator operates at high velocity, then productivity is improved, but the force at mechanical contact increases causing deformation
Solution Approach 1:
The patent applies periodic monitoring of velocity and position parameters, with the operation state recognizing unit continuously detecting arm state and the actuator control unit periodically adjusting control commands. This periodic control maintains high productivity through rapid operation while preventing deformation through continuous velocity-based force management.
Solution Approach 2:
The patent allows the arm to reach the exact mechanical stopper contact point (excessive position action) while controlling the velocity to manage contact force. By permitting full range of motion but limiting the rate of contact through velocity control, the system achieves both high productivity and prevention of deformation.
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
The system effectively prevents deformation and damage by controlling the actuator's operation to decelerate the movable member before contact, ensuring the force at contact is within safe limits, thereby utilizing the maximum operation range of the movable member.
Implementation Method 1
the movable member continues to move by an inertia force but the movable member is deaccelerated by a constant resistance force applied to the movable member by the actuator
Data Source
AI summary
Provided are an operation control system and an operation control method for a movable member, which allow the movable range of the movable member to be utilized to the maximum while deformation of a mechanical element is prevented or reduced. An operation control system 1 includes: a movable member 26 having first mechanical elements 261, 262; an actuator 25 which moves the movable member 26 at a variable velocity; and a second mechanical element 27 which is fixed at a position so as to be capable of making contact with the first mechanical elements 261, 262. When the position and the velocity of the first mechanical element 261 or 262 depart from a predetermined allowable range in a two-dimensional coordinate system expressed by a position and a velocity, a stop instruction is outputted to the actuator 25.