Piezoelectric End Effector for Constant Pressing Force Control
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Solution Overview
Problem
Existing robot hand control devices face challenges in reducing weight due to the integration of force sensors, which complicates fine force control and collision avoidance.
Innovation Solution
The end effector incorporates a piezoelectric element-driven actuator, allowing for constant pressing force control by adjusting drive voltage, reducing the need for heavy force sensors and enabling lightweight design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a force sensor is mounted on the robot hand to enable fine force control and collision avoidance, then force control capability is improved, but the weight of the robot hand increases
Solution Approach 1:
The patent extracts the force sensing function from the robot hand structure and relocates it to the control device. The robot hand controller includes a force sensor that detects forces applied to the robot hand, and a controller that calculates actual pressing force by subtracting gravitational force from the detected force. This extraction eliminates the need to mount heavy force sensors on the robot hand while maintaining force control capability.
Solution Approach 2:
The patent introduces an intermediary computational approach where the control device acts as a mediator between the force sensor and the robot hand. The controller calculates the actual pressing force by processing sensor data and compensating for gravitational effects, enabling accurate force control without direct force sensing at the hand level.
2Measurement precision
If three actuators with force sensors are integrated into the robot hand for fine force control in three axial directions, then force control precision is improved, but device complexity and weight increase
Solution Approach 1:
The patent extracts the force sensing and calculation functions from the robot hand actuators and relocates them to the control device. The controller receives detection signals from the force sensor, calculates the actual pressing force by compensating for gravitational effects, and generates control signals accordingly. This extraction significantly reduces device complexity while maintaining force control precision.
Solution Approach 2:
The patent implements a feedback control mechanism where the controller continuously receives force detection signals, calculates the actual pressing force by subtracting gravitational force, compares it with the target pressing force, and adjusts the actuator output accordingly. This feedback loop maintains high force control precision without requiring complex integrated sensing in each actuator.
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 allows for precise control of pressing force, enhancing the robot's ability to perform tasks like polishing with high accuracy while significantly reducing the end effector's weight, comparable to systems with electromagnetic motors.
Implementation Method 1
an actuator that is between the joint section and the working section and moves the working section in a first direction in which the joint section and the working section are aligned, and a piezoelectric element that drives the actuator
Data Source
AI summary
The end effector 10 includes a joint section 11 connected to a robotic arm 220, a working section 14 for performing work on an object 500, an actuator 40 is located between the joint section 11 and the working section 14 and moves the working section 14 in a first direction in which the joint section 11 and the working section 14 are aligned, a piezoelectric element 45 that drives an actuator 40.