Application Cases

[Overview]

In this study, a power amplifier was used to build a static and dynamic testing platform for the sensor. To address the demand for high tangential sensitivity and fast response in slip detection during robotic grasping, as well as the shortcomings of existing magnetic tactile sensors in this regard, this study proposes a novel arc-shaped tactile sensor based on a centripetal-folded magnetized film. The sensor consists of an arc-shaped magnetic film, a silicone elastomer, and tunnel magnetoresistance (TMR) elements. Through a unique centripetal folded magnetization process, a high-gradient magnetic field is constructed in the sensitive region. By establishing a force–magnetic–electric conversion model and conducting experimental verification, the sensor achieves highly sensitive and fast linear perception of both normal and tangential forces, and is successfully applied to real-time detection of pull-slip and rotational slip in a robotic gripper, providing an effective solution for grasp-stability control.

Experiment Name: Static and Dynamic Output Characterization of Normal/Tangential Forces Based on a Centripetal-Folded Magnetized Arc-Shaped Tactile Sensor, and Slip Detection Experiment on a Robotic Gripper

Experiment Objective: This study aims to verify the performance of the proposed centripetal-folded magnetized arc-shaped tactile sensor. By building a static and dynamic testing platform, the study focuses on verifying the sensor's linear output, sensitivity, response time, and stability under normal and tangential forces, evaluating the accuracy of its force–voltage model, and verifying its application potential in real-time detection of pull-slip and rotational-slip phenomena through robotic-gripper integration experiments, thereby providing an effective sensing scheme for tactile perception and slip warning in precision robotic grasping.

Test Equipment: Normal/tangential force static and dynamic characterization test system (digital push-pull gauge, signal generator, power amplifier, modal shaker), signal acquisition and processing system (DC regulated power supply, data acquisition card, PC), and slip detection application verification system (6-axis robotic arm, three-finger adaptive robotic gripper).

Experiment Procedure: In this study, the performance of the arc-shaped tactile sensor was systematically verified by constructing a sensor force–magnetic–electric conversion model, combined with static/dynamic experiments and integration tests. At the theoretical level, an output voltage model under normal and tangential forces was established. Experimentally, static characterization of normal/tangential forces and dynamic response characterization tests were conducted in sequence, and finally the sensor was integrated into a robotic gripper for pull-slip and rotational-slip detection. The results show that the sensor achieved highly sensitive and fast linear perception of normal and tangential forces, and successfully identified slip onset and friction state changes during the grasping process, verifying its application value in tactile perception and state feedback for precision robotic grasping.

Dynamic Output Test System Block Diagram of the Arc-Shaped Magnetic Tactile Sensor

Figure 1. Dynamic output test system block diagram of the arc-shaped magnetic tactile sensor

Experiment Results: The proposed arc-shaped tactile sensor achieved high-sensitivity and fast perception of normal force (19.2 mV/N) and tangential force (93.3 mV/N), with response times of 38 ms and 34 ms, respectively. Experimental data showed a high degree of agreement with the theoretical model. The sensor performed stably in dynamic tests, and after integration into the robotic gripper, successfully achieved sensitive and real-time detection of pull-slip and rotational slip.

Figure 2. Static tangential force experimental curve of the arc-shaped magnetic tactile sensor

Figure 3. Dynamic response experiment of the arc-shaped magnetic tactile sensor

Product Advantages of Aigtek Power Amplifiers in This Application:

1. Wide bandwidth and flat response — Precisely covers the frequency range required for sensor dynamic testing, ensuring accuracy in frequency-response characteristic evaluation.

2. High power output capability — Drives the modal shaker to generate dynamic forces of sufficient amplitude, covering the full sensor measurement range.

3. Low distortion and high output stability — Ensures pure dynamic excitation waveforms.

[Recommended Product]: ATA-300/3000 Series Power Amplifier

Figure: Specifications of the ATA-300/3000 Series Power Amplifier

The experimental materials in this article were compiled and published by Xi'an Aigtek Electronics. Aigtek has become an instrumentation supplier with a broad product portfolio and considerable scale in the industry; demonstration units are available with free trial support. Xi'an Aigtek Electronics is a high-tech enterprise specializing in the R&D, manufacturing, and sales of electronic test instruments including power amplifiers, high-voltage amplifiers, power signal sources, preamplifier/miniature signal amplifiers, high-precision voltage sources, and high-precision current sources.