Robotic End-Effector Force Limiting With Gravity Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robotic systems face challenges in precisely controlling actuation force on contoured surfaces due to changing gravitational forces, which can lead to errors in force limitations and potential damage to manufactured items, as a single force limitation parameter is insufficient for both upward and downward movements.
Innovation Solution
A system with adaptable force limits that incorporates an orientation detector to adjust force thresholds based on the changing angle between the gravitational vector and the actuation force vector, ensuring accurate force control and preventing excessive force application by using a force limitation device coupled with motors and accelerometers to monitor and adjust the force limits accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single force limitation parameter is used, then the device complexity is reduced, but the manufacturing precision deteriorates due to insufficient force control on contoured surfaces
Solution Approach 1:
The force limitation parameter is transformed from a static single value to a dynamic value that changes with the end effector's orientation. The controller continuously adjusts the force limitation parameter based on real-time orientation data from the orientation detector, enabling the system to adapt to varying gravitational effects while maintaining precise force control on contoured surfaces.
Solution Approach 2:
The system changes the force limitation parameter based on the end effector's orientation angle relative to gravity. By detecting orientation changes and correspondingly adjusting the force limitation parameter, the system accounts for varying gravitational forces during upward and downward movements, thereby maintaining manufacturing precision without requiring overly complex hardware.
2Adaptability or versatility
If the end effector moves on contoured surfaces, then the adaptability is improved, but the force control accuracy deteriorates due to changing gravitational effects
Solution Approach 1:
The system implements a feedback loop where the orientation detector continuously monitors the end effector's orientation, and the controller uses this information to adjust the force limitation parameter in real-time. This feedback mechanism ensures that force control accuracy is maintained despite changes in gravitational effects during movement on contoured surfaces.
Solution Approach 2:
The force limitation parameter is made dynamic by continuously updating it based on the end effector's current orientation. This dynamic adjustment allows the system to adapt to varying gravitational forces during upward and downward movements, maintaining force control accuracy across different positions on contoured surfaces.
3Ease of operation
If force limitation is applied without gravitational compensation, then the ease of operation is improved, but the reliability deteriorates due to potential damage from excessive force
Solution Approach 1:
The system automatically compensates for gravitational effects by using the orientation detector and controller to adjust the force limitation parameter without requiring manual intervention. This self-adjusting mechanism maintains reliability by preventing excessive force application while keeping the operation simple, as the compensation happens autonomously based on detected orientation.
Solution Approach 2:
The force limitation parameter is automatically changed based on the end effector's orientation relative to gravity. This automatic parameter adjustment ensures that the force limitation adapts to gravitational variations during upward and downward movements, preventing damage while maintaining ease of operation without manual calibration.
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 enables precise control of actuation forces on contoured surfaces, preventing damage by accounting for gravitational changes, ensuring safe and accurate operation of robotic end-effectors across varying orientations and movements.
Implementation Method 1
the effect of gravity on the package changes. Thus a force required by the motor for moving the package upward along a contoured surface will be different than a force required for moving the same package downward
Implementation Method 2
an accelerometer coupled to the actuator is configured to detect a change in an angle between a gravitational vector acting on the end effector and the force vector of the actuator
Data Source
Figure 1~2C
Figure 3~4
Figure 5
AI summary
A system and method for maneuvering a robotic end-effector using one or more motors that have a force limiter that is adaptable to take into account any effects of a changing gravitational force as the system moves. In one embodiment, the system includes an actuator, such as a drive motor, for applying a force vector to actuate a function of the end effector, such as moving the end-effector along a track that is attached to a contoured surface. Further, a force limiter coupled to the actuator is configured to interrupt the actuating if the force exceeds a first threshold. Further, the system includes an orientation detector to determine any changes in orientation with respect to gravity so as to adjust the force limit accordingly. Thus, if the force limiter determines that a threshold has been exceeded, the force limiter may limit or interrupt the motion while taking changing gravitational forces into account.