Mono-Axial Sensor Grip Device for Slip Detection
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Solution Overview
Problem
Existing grip devices for robots face challenges in detecting slip between the device and objects due to the high cost and large size of multiaxial and array-type force sensors, which can lead to object dropping during movement.
Innovation Solution
A grip device utilizing a plurality of mono-axial force sensors positioned on inclined surfaces of the gripping fingers, along with a processor that calculates a force vector to adjust the gripping force, and optionally includes a camera for object property identification and a learning model for determining optimal gripping forces to prevent slip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiaxial force sensors or array-type force sensors are used to detect slip, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent divides the force sensing function into multiple independent mono-axial force sensors, each measuring force in a specific direction. By segmenting the sensing task across multiple simple sensors rather than using a single complex multiaxial sensor, the system achieves comprehensive force detection while reducing individual sensor complexity and cost.
Solution Approach 2:
The patent introduces an intermediary computational process that calculates the force vector from the readings of multiple mono-axial sensors. This intermediary calculation layer transforms simple scalar measurements into a comprehensive vector representation, enabling slip detection without requiring complex multiaxial sensors directly.
2Measurement precision
If multiaxial force sensors are used to detect slip, then measurement precision is improved, but device size increases
Solution Approach 1:
The patent segments the force sensing function into multiple small mono-axial sensors distributed at different locations and orientations. This segmentation allows the system to achieve comprehensive three-dimensional force detection using multiple compact sensors rather than a single large multiaxial sensor, thereby reducing overall system volume.
3Reliability
If gripping force is increased to prevent slip, then reliability is improved, but object damage risk increases
Solution Approach 1:
The patent implements a feedback control system that continuously monitors force sensor readings and adjusts the gripping force accordingly. By measuring the actual forces on the object and comparing them against thresholds, the system dynamically adjusts grip strength to maintain reliability while preventing excessive force that could damage the object.
Solution Approach 2:
The patent transitions from a static gripping force approach to a dynamic adjustment mechanism. The gripping force is continuously adapted based on real-time force sensor measurements and slip detection, allowing the system to apply minimal necessary force for stable gripping while avoiding damage from excessive force.
Data Source
AI summary
A grip device includes a first finger with a groove on a gripping surface thereof; a second finger facing the first finger; a middle member inserted into the groove of the first finger and covering the gripping surface; a plurality of mono-axial force sensors each positioned on one of a plurality of inclined surfaces of the groove and configured to detect a force applied to the middle member; a driving motor configured to adjust a gripping force of the first finger and the second finger; and a processor. The processor is configured to calculate a force vector applied to the middle member based on sensing values received from the force sensors, and, based on a force component of the force vector in a direction parallel to a surface of the middle member being less than a preset value, apply a greater gripping force by the first and second fingers.