Using maximum likelihood to calibrate a six-DOF force/torque sensor

Microsystem Technologies - This study presents a new six-DOF force/torque sensor and its calibration method. This calibration method apply the method of so-called maximum likelihood estimation...     

MEMS Sensor for In Situ TEM Atomic Force Microscopy

Here, we present a MEMS atomic force microscope sensor for use inside a transmission electron microscope (TEM). This enables direct in situ TEM force measurements in the nanonewton range and thus mechanical characterization of nanosized structures. The main design challenges of the system and sensor are to reach a high sensitivity and to make a compact design that allows the sensor to be fitted in the narrow dimensions of the pole gap inside the TEM. In order to miniaturize the sensing device, an integrated detection with piezoresistive elements arranged in a full Wheatstone bridge was used. Fabrication of the sensor was done using standard micromachining techniques, such as ion implantation, oxide growth and deep reactive ion etch. We also present in situ TEM force measurements on nanotubes, which demonstrate the ability to measure spring constants of nanoscale systems.     

六自由度并联机器人动力学方程

本文研究了6自由度并联机器人机构的显式动力学方程的建立。文中首先导出了构件6维惯性力矢关于主动副速度、加速度的显表达式,引入了仅与机构位形和质量分布有关的一、二阶惯性影响系数,进而应用达朗伯原理方便地建立起6自由度并联机器人的显式动力学方程。最后进行了实例计算。     

Motorized CPM/CAM physiotherapy device with sliding-mode Fuzzy Neural Network control loop

Continuous passive motion (CPM) and controllable active motion (CAM) physiotherapy devices promote rehabilitation of damaged joints. This paper presents a computerized CPM/CAM system that obviates the need for mechanical resistance devices such as springs. The system is controlled by a computer which performs sliding-mode Fuzzy Neural Network (FNN) calculations online. CAM-type resistance force is generated by the active performance of an electric motor which is controlled so as to oppose the motion of the patient's leg. A force sensor under the patient's foot on the device pedal provides data for feedback in a sliding-mode FNN control loop built around the motor. Via an active impedance control feedback system, the controller drives the motor to behave similarly to a damped spring by generating and controlling the amplitude and direction of the pedal force in relation to the patient's leg. Experiments demonstrate the high sensitivity and speed of the device. The PC-based feedback nature of the control loop means that sophisticated auto-adaptable CPM/CAM custom-designed physiotherapy becomes possible. The computer base also allows extensive data recording, data analysis and network-connected remote patient monitoring.     

基于QFD/TRIZ/FUZZY集成技术的微摩擦测试仪力传感器设计

基于QFD/TRIZ/FUZZY集成技术,建立了用户需求和设计需求的关系.利用产品创新设计方法解决设计中的技术矛盾,得到创新问题的最优原理解.研究MEMS器件微摩擦测试仪力传感器的质量屋,选取材料强度和材料变形作为创新设计的主要技术矛盾,按照TRIZ方法给出解决冲突的原理解集合,应用模糊层次分析法对各原理解进行评价,得到最优设计方案,验证了该集成方法的可行性.     

微型五维指尖力/力矩传感器的研究

本文介绍了RPJ D型喷浆机器人的机械机构，重点给出了其分布式计算机控 制系统的设计过程．将容错技术、故障诊断技术和抗恶劣环境技术引入喷浆机器人控制系统 中，采用不同的冗余配置方式实现了控制系统规划级和控制级计算机系统高可靠性设计．现 场应用表明，完全满足了喷浆机器人在恶劣环境下工作的要求．     

A micromachined piezoelectric tactile sensor for an endoscopicgrasper-theory, fabrication and experiments

Present-day commercial endoscopic graspers do not have any built-in sensors, thus, the surgeon does not have the necessary tactile feedback to manipulate the tissue safely. This paper presents the design, fabrication, testing, and experimental results of a micromachined tactile sensor, which can be integrated with the tips of commercial endoscopic graspers. The prototype sensor consists of three layers. The top layer is made of micromachined silicon with a rigid tooth-like structure similar to the present-day endoscopic grasper. The bottom layer is made of flat Plexiglass serving as a substrate. Packaged between the Plexiglass and the silicon is a patterned Polyvinglidene Fluoride (PVDF) film. The proposed sensor exhibits high sensitivity, a large dynamic range, and a high signal-to-noise ratio. Through experimental results, it is shown that the magnitude and position of an applied force can be determined from the magnitude and slope of the output signals from the PVDF sensing elements. Structural analysis is also performed using the finite-element method, and the results are compared with the experimental analysis. The advantages and limitations of this sensor are also reported. A discussion of how the design of the sensor can be integrated with the design of an endoscopic grasper is also presented     

一种用于微型六维力传感器的集成式应变计设计

为实现六维力传感器的微型化与集成化,提出了一种新型的集成式应变计．该应变计由6组敏感栅组成,可与薄壁圆筒型弹性体组成微型六维力传感器．文中介绍了信号调理电路和数字化电路的组成．采用微型数字信号处理器和刚柔结合的电路板实现了传感器的电路集成．对传感器进行了静动态标定并分析了实验结果．     

一种小量程六维力传感器的设计与分析

针对外科手术力觉信息采集对多维力传感器提出的低量程和高分辨率的要求,对常规的十字梁六维力传感器进行结构改进,设计了一种具有滑移结构的低维间耦合的小量程六维力传感器。分析了传感器结构抑制维间耦合的机理,通过有限元方法分析了其受力变形情况。标定实验表明:该六维力传感器非线性误差与维间耦合误差均小于2%,具有高灵敏度、高分辨率和低维间耦合的特点。     

Parylene surface-micromachined membranes for sensor applications

This paper reports the design, fabrication process, and testing results of Parylene surface-micromachined membranes with integrated strain gauges or thermal resistors made of thin film metals. The membrane is suspended above the substrate. This paper demonstrates the feasibility of sensor applications with a force (tactile) sensor and a fluid shear stress sensor.     

A Stewart Platform-Based System for Ankle Telerehabilitation

The Rutgers Ankle is a Stewart platform-type haptic interface designed for use in rehabilitation. The system supplies six-DOF resistive forces in response to virtual reality-based exercises running on a host PC. The Stewart platform uses double-acting pneumatic cylinders, linear potentiometers as position sensors, and a six-DOF force sensor. The Rutgers Ankle controller contains an embedded Pentium board, pneumatic solenoid valves, valve controllers, and associated signal conditioning electronics. Communication with the host PC is over a standard RS232 line. The platform movement and output forces are transparently recorded by the host PC in a database. This database can be accessed remotely over the Internet. Thus, the Rutgers Ankle Orthopedic Rehabilitation Interface will allow patients to exercise at home while being monitored remotely by therapists. A prototype was constructed, and proof-of-concept trials were conducted at the University of Medicine and Dentistry of New Jersey. The results indicate that the system works well as a diagnostic tool. The subjective evaluation by patients was very positive. Further medical trials are needed before the system clinical efficacy in rehabilitation can be established.     

基于红外传感器与压电电缆AGV综合防护系统研究

针对传统AGV中超声波避障和机械结构防撞防护系统不足,提出了基于红外传感器避障和基于压电电缆的防撞综合防撞系统的设计方法,并对红外与压电电缆传感器构成的AGV综合防护系统进行了刹车和碰撞实验研究。经实验证明:基于红外与压电电缆传感器AGV综合防护系统具有响应灵敏度高、刹车距离短、碰撞触发力小特点,满足实际应用要求。     

A novel six-component force sensor of good measurement isotropy and sensitivities

In this work, a novel six-component force sensor with its force-sensing member in the form of four identical T-shaped bars is presented. The force-sensing member is subjected to finite element analysis in conjunction with a design optimization for high measurement sensitivities. Although significant measurement couplings exist in this six-component force sensor, however, they distribute only in a few sparse places in the calibration matrix, making the calculations for the force components relatively easy and quick. The condition number under the full rated loading conditions for this sensor is 1.543, which represents a rather good measurement isotropy, as compared to approximately 2–4 for a Maltese crossbar sensor under similar conditions. In addition, only 20 strain gauges are required in the design, which is less than that used in a Maltese crossbar type sensor, in which at least 24 strain gauges are used.     

多感知机器人夹持器设计

介绍了一种具有力觉、触觉和位置信息的机器人夹持器设计。讨论了力觉传感器、触觉传感器和位置传感器的设计与实现，概述了夹持器的机械结构及其控制系统设计。     

Integrated Design of an Ionic Polymer–Metal Composite Actuator/Sensor

We are studying the robotic application of ionic polymer–metal composite (IPMC). The characteristics of IPMC greatly depend on the type of counterions, and it is considered that the performance of the actuators can be improved by combining the actuators with several types of counterions and applying an integrated control. IPMC also has a sensor function, as the IPMC film generates an electromotive force when it is deformed. It has the possibility to be integrated into an IPMC actuator with soft actuation. In this paper, we consider an integrated design of an IPMC actuator/sensor, and investigate control of the combined IPMC actuators using H _∞ control and the construction of an IPMC sensor system.     

基于嵌入式系统和CAN总线的检修机械臂控制系统

以蒸汽发生器六自由度检修机械臂为应用背景,给出六自由度检修机械臂的硬件体系结构和上下位机软件设计方法。本设计方法在检修机械臂控制系统的设计开发中取得了良好的效果。     

MEMS tri-axial force sensor with an integrated mechanical stopper for guidewire applications

This paper describes the design and characterization of a micro-electro-mechanical systems tri-axial force sensor that can be mounted on the tip of an 1-French guidewire (0.014″). Piezoresistive silicon nanowires (SiNWs) are embedded into four beams forming a cross-shape to allow the detection of forces in three axes. The electrical resistance changes in the four SiNWs are used to decode arbitrary force applied onto the force sensor. Finite element analysis was used in the structural design of the force sensor. Robustness of the force sensor is improved due to the novel design of incorporating a mechanical stopper on the tip of the stylus. Flip chip bonding, using gold stud bumps, is used to mount the force sensor on a substrate for characterization and to simplify the assembly process. The sensor is robust enough to withstand normal forces higher than 20 gf. The proposed sensor can be used for new medical applications in vascular interventions and robotic surgeries.     

空间多维力/力矩传感器关键技术研究综述

空间多维力/力矩传感器安装在空间机械臂的关节部位，随航天器一起发射进入太空，面临强振动、高冲击和大温差等复杂的恶劣环境,普通地面使用的多维力/力矩传感器要突破这些恶劣环境的限制方可使用。介绍了空间多维力/力矩传感器的研究发展现状，对空间多维力/力矩传感器在弹性体结构设计、过载保护、容错和温度补偿等方面的关键技术研究现状进行了详细阐述，并以此为基础对未来空间多维力/力矩传感器的研究方向提出了几点建议。     

小型高可靠分体式多冗余线位移传感器研制

为了满足新型战略导弹武器的研制需求,要求伺服机构结构紧凑,集成度高,并能够适应恶劣的工作环境和有限的空间结构,实现伺服作动器齿条位移的测量及反馈。一种小型高可靠分体式多冗余线位移传感器的研制,在传统的分体式线位移传感器的基础上,通过四冗余的结构设计,印制电阻膜的设计,零位输出可调的设计,多指型电刷受力的优化设计,实现了线位移传感器的结构小型化和紧凑化的冗余功能,能够耐高温,工作寿命长,线性精度高的性能。试验和仿真分析表明设计技术方案有效可行,能够满足伺服系统的要求。     

Design of an optical soft sensor for measuring fingertip force and contact recognition

Among the various ways to estimate user intention in hand exoskeletons, a contact force measurement is definitely the most straightforward and intuitive method. A force sensor, located at the center of a fingertip usually, hinders the tactile sensation of the user by blocking the contact between an object and the fingertip. To overcome this problem, a soft force sensor with horse shoe shape is utilized to measure the contact force and provide the tactile sensation to the user. This work presents the mechanical design, implementation and evaluation of a soft fingertip force sensor. To maximize tactile sensation of the user, we adopted a horse shoe shape structure to leave the finger pad exposed. An optical sensing mechanism was selected for its relatively fast response compared to other soft sensors. The whole sensor system has a soft exterior providing flexibility and a user-friendly interface. To evaluate the sensor’s performance, we carried out sensor optimization process and calibration experiment with a customized test bed. Then, we investigated both static and dynamic response and observed the mechanical behavior and light intensity changes caused by the cross sectional shape and base/agent ratio of PDMS. Lastly, we applied the proposed sensor to the glove type fingertip force monitoring system. The sensor estimates the index finger tip force with high accuracy (R ² = 0:96) within 5N range.