Robotic Gripper Closure Control for Fast Grip Without Excess Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robotic grippers face challenges such as high inertia and excessive pinch force during fast closure, early decay of braking mechanisms, difficulty in detecting slipping objects, and cumbersome data connectivity, which can lead to object loss and performance interruptions.
Innovation Solution
A robotic gripper design featuring a DC motor, reduction gear mechanism, and a backdrivable gear system with an encoder and electrically controllable brake, allowing for controlled force application and slip detection, along with a hand-guiding mechanism that interprets operator actions without a pendant, and a connector for reduced cabling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gripper closes at higher speed, then productivity is improved, but the pinch force becomes excessively high and may damage the object
Solution Approach 1:
The patent implements dynamic control of the motor voltage during the closing cycle. The controller adjusts voltage based on the gripper's position and velocity, applying higher voltage during approach and lower voltage during closing to dynamically manage both speed and force throughout the operation
Solution Approach 2:
The system changes operational parameters (voltage, speed, force) based on the closing phase. The controller modifies motor parameters in real-time to maintain optimal closing speed while preventing excessive pinch force that could damage the object
2Reliability
If a brake mechanism is engaged to hold the object, then the motor can be disengaged to prevent overheating, but the brake has a fall or decay time before engagement which may cause object loss
Solution Approach 1:
The brake is engaged in advance before the motor needs to be disengaged. The controller activates the brake mechanism prior to motor shutdown, ensuring the object is secured before the motor is turned off to prevent overheating
Solution Approach 2:
The system maintains continuous control over the gripping action by coordinating brake engagement with motor operation. The brake and motor work in a continuous sequence to ensure the object remains securely held throughout the operation
3Reliability
If an encoder and control system are used to detect slippage, then object loss is prevented, but the device complexity increases
Solution Approach 1:
The encoder provides continuous feedback on the gripper's position and the object's grip status. The controller monitors this feedback to detect slippage conditions and responds by adjusting the gripping force or re-engaging the brake to prevent object loss
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 gripper achieves controlled and efficient object handling with reduced risk of slipping or loss, improved learning efficiency, and enhanced reliability through precise force management and data connectivity, while minimizing the risk of cabling damage.
Implementation Method 1
DC motor
Implementation Method 2
reduction gear mechanism
Implementation Method 3
electrically controllable brake
Implementation Method 4
encoder
Data Source
AI summary
In one aspect, the present disclosure provides a robot gripper with a closing mechanism that while providing a desirable closing speed avoids exerting a force on the rigid object which is greater than the holding force required to hold the rigid object in the gripper. In another aspect, the present invention provides a robot gripper capable of detecting a slip or loss of an object held by the gripper. In an alternative aspect, the present invention provides a robot gripper capable of being hand guided. In another aspect, the invention provides a robot gripper brake drive circuit with faster operation. In one other aspect, the invention provides a connector for connecting a robot end effector to a robot arm with an adjustable cable.