End-effector sensing device and method

End-Effector Sensing Device and Method

This technology utilizes FEM analysis to strategically place strain gauges within a Maltese cross-shaped sensor frame. It measures deformations caused by loads during object gripping to calculate 3-DOF (Fz, Tz, Tx) force/torque data. The collected signals are processed via a data acquisition board using decoupling algorithms to compensate for physical cross-talk, ensuring precise measurements.

Conventional grippers are typically limited to simple compression force measurement, making it difficult to precisely measure force and torque at the tool-tip contact surface. Furthermore, tactile sensors often suffer from slow response times, rendering them unsuitable for high-speed repetitive tasks. Additionally, attaching individual sensors to multi-fingered robotic hands leads to complex structural and control requirements.

This technology integrates a Maltese cross-shaped sensor frame with strain gauges for deformation measurement and utilizes an integrated wiring board to achieve a compact design. Analog signals acquired from the optimally placed strain gauges (via FEM analysis) are processed by a data acquisition board, which uses a decoupling matrix to separate and convert them into digital force/torque data for each axis. Applicable to robotic gripping, precision measurement, and automated equipment, this solution enhances the accuracy and response rate of force and torque measurement in robotic grippers.

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Key Features:

• A sensor frame comprising an outer frame and internal beams that intersect within the outer frame; it is positioned on the inner surface of the end-effector, features a Maltese cross shape, and includes a protrusion at the intersection of the internal beams where the tool-tip is fastened.
• An end-effector sensing device including a wiring board that connects to the strain gauges via Teflon-wrapped wires and is integrated into the sensor frame.
• A data acquisition board that receives calibration commands and transmits them to the sensing device.
• A plurality of strain gauges that deform when the end-effector grips an object.

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of safety modules with a maximum output range of 150Nm and force-torque/joint sensor technology for dual-arm collaborative robots.