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Li J, Ma R, Bai J. High-Precision Chromatic Confocal Technologies: A Review. MICROMACHINES 2024; 15:1224. [PMID: 39459098 DOI: 10.3390/mi15101224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Revised: 09/22/2024] [Accepted: 09/24/2024] [Indexed: 10/28/2024]
Abstract
Chromatic confocal technology is widely used for precise, steady, and efficient displacement measurement in many industrial fields. It employs the confocal and dispersion principles to encode axial positions with the wavelengths of the reflected broad spectrum. The typical chromatic confocal sensor includes a light source, a dispersion objective, conjugate pinholes, and a spectral detection device. This study offers an overview of the current research on chromatic confocal technology. Because of its good performance in displacement detection, chromatic confocal technology has been widely used in contour measurement, biomedical imaging, and thickness measurements, as part of global and professional research. Due to its structural flexibility, it is also easily integrated into industrial equipment for in-machine and online profile measurements. It holds significant potential for future applications in industrial manufacturing and scientific research. However, there are also some challenges to be explored in terms of the broadband light source, dispersive optics design, and the balance between speed and accuracy in signal processing.
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Affiliation(s)
- Jingwen Li
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Rui Ma
- Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Jiao Bai
- Institute of Materials, China Academy of Engineering Physics, Mianyang 621907, China
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2
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Ma T, Yang S, Xu Y, Liu D, Hou J, Liu Y. Analysis and Correction of Measurement Error of Spherical Capacitive Sensor Caused by Assembly Error of the Inner Frame in the Aeronautical Optoelectronic Pod. SENSORS (BASEL, SWITZERLAND) 2022; 22:9543. [PMID: 36502242 PMCID: PMC9738035 DOI: 10.3390/s22239543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/02/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
The ball joint is a multi-degree-of-freedom transmission pair, if it can replace the inner frame in the aviation photoelectric pod to carry the optical load, which will greatly simplify the system structure of the photoelectric pod and reduce the space occupied by the inner frame. However, installation errors in ball joint siting introduce nonlinear errors that are difficult to correct and two degree of freedom angular displacement of the ball joint is difficult to detect, which limits application in the precision control of two degrees of freedom systems. Studies of spherical capacitive sensors to date have not tested sensors for use in an inner frame stabilisation mechanism nor have they analysed the influence of installation error on sensor output. A two-axis angular experimental device was designed to measure the performance of a ball joint capacitive sensor in a frame stabilisation mechanism in an aeronautical optoelectronic pod, and a mathematical model to compensate for ball joint capacitive sensor installation error was created and tested. The experimental results show that the resolution of the capacitive sensor was 0.02° in the operating range ±4°, the repeatability factor was 0.86%, and the pulse response time was 39 μs. The designed capacitive sensor has a simple structure, high measurement accuracy, and strong robustness, and it can be integrated into ball joint applications in the frames of aeronautical photoelectric pods.
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Affiliation(s)
- Tianxiang Ma
- Information and Communication Engineering, School of Electronic and Information Engineering, Changchun University of Science and Technology, Changchun 130022, China
| | - Shengqi Yang
- Key Laboratory of Airborne Optical Imaging and Measurement, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongsen Xu
- Key Laboratory of Airborne Optical Imaging and Measurement, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Dachuan Liu
- Jiuquan Satellite Launch Centre, Jiuquan 732750, China
| | - Jinghua Hou
- Jiuquan Satellite Launch Centre, Jiuquan 732750, China
| | - Yunqing Liu
- Information and Communication Engineering, School of Electronic and Information Engineering, Changchun University of Science and Technology, Changchun 130022, China
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Huang J, Dai K, Yin Y, Chen Z, You Z, Wang X. Design and Fabrication of Interdigital Supercapacitors as Force/Acceleration Sensors. SENSORS (BASEL, SWITZERLAND) 2022; 22:9268. [PMID: 36501970 PMCID: PMC9739844 DOI: 10.3390/s22239268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/24/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
The integrated device for energy supply and sensing (IDESS) is a potential candidate for relieving the energy and space burdens caused by the rising integration degrees of microsystems. In this article, we propose a force sensor based on an interdigital supercapacitor (IDTSC). The capacitance and internal resistance of the IDTSC change under external loads, resulting in a transient current fluctuation at a constant bias voltage, which can be used to sense external force/acceleration. The IDTSC showed a specific energy and specific power of 4.16 Wh/kg and 22.26 W/kg (at 0.1 A/g), respectively, which could maintain an essential energy supply. According to the simulation analysis, the designed IDTSC's current response exhibited good linearity with the external force. In addition, benefiting from its light weight and the applied gel electrolytes, the IDTSC showed good high-g impact sensing performance (from 9.9 × 103× g to 3.2 × 104× g). This work demonstrated the feasibility of realizing an integrated energy supply and force-sensing device by empowering energy storage devices with sensing capabilities.
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Affiliation(s)
- Jue Huang
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- Beijing Advanced Innovation Center for Integrated Circuits, Beijing 100084, China
| | - Keren Dai
- ZNDY of Ministerial Key Laboratory, School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yajiang Yin
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- Beijing Advanced Innovation Center for Integrated Circuits, Beijing 100084, China
| | - Zhaorong Chen
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- Beijing Advanced Innovation Center for Integrated Circuits, Beijing 100084, China
| | - Zheng You
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- Beijing Advanced Innovation Center for Integrated Circuits, Beijing 100084, China
| | - Xiaofeng Wang
- Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- Beijing Advanced Innovation Center for Integrated Circuits, Beijing 100084, China
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Wang W, Qiu W, Yang H, Lu K, Chen Z, Ju B. Error Analysis of a Spherical Capacitive Sensor for the Micro-Clearance Detection in Spherical Joints. MICROMACHINES 2020; 11:mi11090837. [PMID: 32899156 PMCID: PMC7570230 DOI: 10.3390/mi11090837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 08/30/2020] [Accepted: 09/01/2020] [Indexed: 11/16/2022]
Abstract
Spherical joints have attracted increasing interest in the engineering applications of machine tools, industrial robots, medical equipment, and so on. As one of the promising methods of detecting the micro-clearance in spherical joints, the measurement accuracy of a spherical capacitive sensor could be affected by imperfectness during the manufacturing and installation of the sensor. This work presents error analysis of a spherical capacitive sensor with a differential structure and explores the dependence of the differential capacitance on manufacturing and the installation imperfectness. Five error sources are examined: the shape of the ball and the capacitive plate, the axial and radial offset of the plate, and the inclined installation of the plate. The mathematical models for calculating the capacitance errors of the spherical capacitive sensor are deduced and validated through a simulation using Ansoft Maxwell. The results show that the measurement accuracy of the spherical capacitive sensor is significantly affected by the shape of plates and ball, the axial offset, and the inclined angle of the plate. In contrast, the effect of the radial offset of the plate is quite small.
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Affiliation(s)
- Wen Wang
- School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; (W.W.); (W.Q.); (K.L.); (Z.C.)
| | - Wenjun Qiu
- School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; (W.W.); (W.Q.); (K.L.); (Z.C.)
| | - He Yang
- School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; (W.W.); (W.Q.); (K.L.); (Z.C.)
- Correspondence: ; Tel.: +86-571-8691-9155
| | - Keqing Lu
- School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; (W.W.); (W.Q.); (K.L.); (Z.C.)
| | - Zhanfeng Chen
- School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; (W.W.); (W.Q.); (K.L.); (Z.C.)
| | - Bingfeng Ju
- School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China;
- State Key Lab of Fluid Power & Mechatronic Systems, Zhejiang University, Hangzhou 310027, China
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A New Method for Measuring the Rotational Angles of a Precision Spherical Joint Using Eddy Current Sensors. SENSORS 2020; 20:s20144020. [PMID: 32698341 PMCID: PMC7412033 DOI: 10.3390/s20144020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 11/23/2022]
Abstract
Precision spherical joint is a spherical motion pair that can realize rotation with three degrees of freedom. This joint is widely used in robots, parallel mechanisms, and high-end medical equipment, as well as in aerospace and other fields. However, the rotation orientation and angle cannot be determined when the joint is in passive motion. The real-time determination of the rotation orientation and angle is crucial to the improvement of the motion control accuracy of the equipment where the joint is installed in. In this study, a new measurement method that utilizes eddy current sensors is proposed to identify the special features of the joint ball and realize angle measurements indirectly. The basic idea is to manufacture the specific shape features on the ball without affecting its movement accuracy and mechanical performance. An eddy current sensor array is distributed in the ball socket. When the ball head rotates, the features on the ball opposite to the sensor, as well as the output signal of every eddy current sensor, change. The measurement model that establishes the relationship between the output signal of the eddy current sensor array and the rotation direction and angle of the ball head is constructed by learning and training an artificial neural network. A prototype is developed using the proposed scheme, and the model simulation and feasibility experiment are subsequently performed. Results show that the root mean square angular error of a single axis within a range of ±14° is approximately 20 min, which suggests the feasibility of the proposed method.
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