Picking Arm Force Compensation for Accurate Collision Detection
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Solution Overview
Problem
Existing picking apparatuses face difficulties in detecting collisions during the conveyance of objects, which can result in dropped or damaged articles.
Innovation Solution
A picking apparatus equipped with a gripper, arm, detector, and control unit that calculates and subtracts gravitational and inertial forces from sensed forces to detect potential collisions, using pre-determined compensation parameters based on the object's mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If collision detection is performed during object conveyance, then operational safety is improved, but detection accuracy deteriorates due to interference from gravitational and inertial forces
Solution Approach 1:
The patent extracts and removes the gravitational force and inertial force components from the total force measured by the detector. By calculating these interference forces separately using known parameters (mass, acceleration, gravity) and subtracting them from the measured force, the system isolates the collision force component, thereby improving detection accuracy while maintaining operational safety
Solution Approach 2:
The control unit acts as an intermediary that processes the raw force measurement by introducing calculated compensation values for gravity and inertia. This intermediary processing step transforms the inaccurate raw measurement into an accurate collision detection signal by mediating between the detector output and the collision determination logic
2Ease of operation
If simple collision determination is implemented, then ease of operation is improved, but detection accuracy deteriorates due to force interference
Solution Approach 1:
The system performs preliminary calculations of gravitational force and inertial force using pre-known parameters (object mass, arm acceleration, gravity constant) before making the collision determination. This preliminary action prepares the compensation values in advance, allowing the final collision check to remain simple while incorporating accurate force compensation
Solution Approach 2:
The control unit uses readily available data (object mass from the calculator, acceleration from motion control, gravity from constants) to self-generate the compensation values needed for accurate collision detection. The system serves itself by utilizing its own operational parameters to correct its measurement errors, maintaining simplicity while improving accuracy
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
Enables accurate and efficient collision detection during object conveyance, reducing the risk of damage and improving operational safety by minimizing the collision threshold value.
Implementation Method 1
The calculator calculates a gravitational force and an inertial force applied to the gripper when the gripper grips and moves the object to be conveyed
Implementation Method 2
The calculator calculates a gravitational force and an inertial force applied to the gripper when the gripper grips and moves the object to be conveyed
Data Source
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AI summary
A picking apparatus in an embodiment includes: a gripper, an arm, a detector, and a control unit. The gripper picks and grips an object to be conveyed. The arm moves the gripper and causes the gripper to convey the object to be conveyed. The detector is attached to the arm and senses a force applied to the gripper. The control unit controls an operation of the gripper and the arm. The control unit includes a calculator and a subtractor. The calculator calculates a gravitational force and an inertial force applied to the gripper when the gripper grips and moves the object to be conveyed using an arithmetic expression including a coefficient determined in accordance with a mass of the object to be conveyed. The subtractor subtracts the gravitational force and the inertial force calculated by the calculator from a force applied to the gripper sensed by the detector.