High precision intelligent flexible grasping front-end with CMOS interface for robots application

• Published in: Science China. Information sciences 2016-03, Vol.59 (3), p.172-182, Article 32203
• Main Authors: Hu, Xiaohui, Zhang, Xu, Liu, Ming, Chen, Yuanfang, Li, Peng, Liu, Jialin, Yao, Zhaolin, Pei, Weihua, Zhang, Chun, Chen, Hongda
• Format: Article
• Language: English
• Subjects: Capacitors; CMOS; CMOS技术; Computer Science; Conditioning; Error detection; Grasping (robotics); Information Systems and Communication Service; Research Paper; Robots; Sandwich structures; Sensitivity; Sensor arrays; Sensors; S接口; Tactile sensors (robotics); 传感器阵列; 前端; 智能; 机器人应用; 触觉传感器; 高精度
• ISSN: 1674-733X; 1869-1919
• DOI: 10.1007/s11432-015-5358-y

This paper presents a high-precision intelligent flexible robot grasping front-end with an integrated capacitive tactile sensor array and a conditioning chip. The capacitive tactile sensor is the primary part of the front-end, it determines the overall performance. The micro-needle array sandwich structure in the tactile sensor increases the repeatability and stability, and ensures the sensitivity. The assembled sensor exhibits a saturation at 10.53 N （421 kPa） with a sensitivity of 1.9%/kPa. Furthermore, a conditioning chip is utilized in a custom readout interface to achieve better performance by reducing signal attenuation, and to increase the compatibility of the front-end. The chip is optimized for the parasitic shunt capacitance in the capacitor array. A dual bidirectional charge-discharge conversion method and a two-port detection method are matched to achieve the goal of reducing the shunting influence, and attenuating the offset voltage or the noise input effects. A prototype of the interface has been fabricated using 180-nm CMOS technology. Sensor with the value of 0.5 pF shunted by capacitors of 47 pF has been detected with an error of 1% within 100 μs.