Qiaokang Liang

A Novel Miniature Four-Dimensional Force/Torque Sensor With Overload Protection Mechanism

Force sensors play a key role in modern technology. Specifically, they can measure the force of mechatronics systems used in automated manufacturing environments, thereby enabling such systems to function effectively, thus facilitating decision making. However, the most current generation of force and torque sensors is complicated and expensive. Moreover, these sensors cannot be used for many applications because they are too brittle to sustain a large load. Accordingly, this paper presents a novel miniature four-dimensional force sensor, whose element is in the form of an E-type membrane connected to double rectangle slices. This sensor is aimed at obtaining the accurate interaction forces, including the normal force, both tangential force terms and the torque about the normal axis, in most applications. Furthermore, the sensor contains the advantages of configuration simplicity, overload protection and high sensitivity. Experiment results demonstrate its strong linearity, weak couplings among dimensions and simple calibration. The maximum nonlinearity errors is 0.18% F.S. and the maximum interference errors is 1.9% F.S.

Multi-Dimensional MEMS/Micro Sensor for Force and Moment Sensing: A Review

The importance of force sensing technologies was recognized in the 1970s. Since then, multidimensional microelectromechanical systems (MEMS)/micro force/moment (F/M) sensors have permeated a wide variety of products. A multidimensional MEMS/micro-F/M sensor can measure the tangential force terms along x-, y-, and z-axis (Fx, Fy and Fz) as well as the moments terms about x-, y-, and z-axis (Mx, My and Mz) simultaneously with micro-Newton and nano-Newtonmeter resolution. This paper presents an overview of MEMS/micro-F/M sensors. This field is critical to many biomedical applications, materials science, industrial automation, dimension measurements in microcomponents, and nanomanufacturing applications, and has attracted great activity in the past 15-25 years. The evaluation of different F/M sensing principles, recent advances in various designs, and their significance and limitations are analyzed through specific examples. Furthermore, current challenges and new area for future applications of micro-F/M sensing technology have been identified.

Design and Analysis of a Sensor System for Cutting Force Measurement in Machining Processes

Multi-component force sensors have infiltrated a wide variety of automation products since the 1970s. However, one seldom finds full-component sensor systems available in the market for cutting force measurement in machine processes. In this paper, a new six-component sensor system with a compact monolithic elastic element (EE) is designed and developed to detect the tangential cutting forces Fx, Fy and Fz (i.e., forces along x-, y-, and z-axis) as well as the cutting moments Mx, My and Mz (i.e., moments about x-, y-, and z-axis) simultaneously. Optimal structural parameters of the EE are carefully designed via simulation-driven optimization. Moreover, a prototype sensor system is fabricated, which is applied to a 5-axis parallel kinematic machining center. Calibration experimental results demonstrate that the system is capable of measuring cutting forces and moments with good linearity while minimizing coupling error. Both the Finite Element Analysis (FEA) and calibration experimental studies validate the high performance of the proposed sensor system that is expected to be adopted into machining processes.

A Potential 4-D Fingertip Force Sensor for an Underwater Robot Manipulator

The latest generation of underwater robots employ manipulators without force sensors. Accordingly, this paper presents a novel 4-D fingertip force sensor based on an E-type membrane for underwater robot manipulators. Specifically, this sensor is aimed at obtaining the accurate interaction force between underwater robot manipulators and other objects. Moreover, a seal technique and natural pressure compensation for the sensor are also described. The experimental results demonstrate strong linearity, high sensitivity, and weak couplings.

Methods and Research for Multi-Component Cutting Force Sensing Devices and Approaches in Machining

Multi-component cutting force sensing systems in manufacturing processes applied to cutting tools are gradually becoming the most significant monitoring indicator. Their signals have been extensively applied to evaluate the machinability of workpiece materials, predict cutter breakage, estimate cutting tool wear, control machine tool chatter, determine stable machining parameters, and improve surface finish. Robust and effective sensing systems with capability of monitoring the cutting force in machine operations in real time are crucial for realizing the full potential of cutting capabilities of computer numerically controlled (CNC) tools. The main objective of this paper is to present a brief review of the existing achievements in the field of multi-component cutting force sensing systems in modern manufacturing.

Design and Analysis of a Novel Six-Component F/T Sensor based on CPM for Passive Compliant Assembly

Abstract This paper presents the design and analysis of a six-component Force/Torque (F/T) sensor whose design is based on the mechanism of the Compliant Parallel Mechanism (CPM). The force sensor is used to measure forces along the x-, y-, and z-axis (Fx, Fy and Fz) and moments about the x-, y-, and z-axis (Mx, My and Mz) simultaneously and to provide passive compliance during parts handling and assembly. Particularly, the structural design, the details of the measuring principle and the kinematics are presented. Afterwards, based on the Design of Experiments (DOE) approach provided by the software ANSYS®, a Finite Element Analysis (FEA) is performed. This analysis is performed with the objective of achieving both high sensitivity and isotropy of the sensor. The results of FEA show that the proposed sensor possesses high performance and robustness.

Miniature robust five-dimensional fingertip force/torque sensor with high performance

This paper proposes an innovative design and investigation for a five-dimensional fingertip force/torque sensor with a dual annular diaphragm. This sensor can be applied to a robot hand to measure forces along the X-, Y- and Z-axes (Fx, Fy and Fz) and moments about the X- and Y-axes (Mx and My) simultaneously. Particularly, the details of the sensing principle, the structural design and the overload protection mechanism are presented. Afterward, based on the design of experiments approach provided by the software ANSYS®, a finite element analysis and an optimization design are performed. These are performed with the objective of achieving both high sensitivity and stiffness of the sensor. Furthermore, static and dynamic calibrations based on the neural network method are carried out. Finally, an application of the developed sensor on a dexterous robot hand is demonstrated. The results of calibration experiments and the application show that the developed sensor possesses high performance and robustness.

Design of a novel six-dimensional force/torque sensor and its calibration based on NN

This paper describes the design of a six-axis force/torque sensor, the purpose of which is to provide decoupled and accurate F/T information for the closed-loop control of the manipulator system. Firstly, the manipulator system and the adopted measuring principle are introduced. Then, a novel static component based on dual annulus diaphragms is presented. At last, the calibration and decoupling test based on Neural Network (NN) is carried out. The results of calibration test show superiority of the structure of the elastic component of the developed sensor and the improvement of the calibration method.

Design and Analysis of a Micromechanical Three-Component Force Sensor for Characterizing and Quantifying Surface Roughness

Abstract Roughness, which can represent the trade-off between manufacturing cost and performance of mechanical components, is a critical predictor of cracks, corrosion and fatigue damage. In order to measure polished or super-finished surfaces, a novel touch probe based on three-component force sensor for characterizing and quantifying surface roughness is proposed by using silicon micromachining technology. The sensor design is based on a cross-beam structure, which ensures that the system possesses high sensitivity and low coupling. The results show that the proposed sensor possesses high sensitivity, low coupling error, and temperature compensation function. The proposed system can be used to investigate micromechanical structures with nanometer accuracy.

Modular design and development methodology for robotic multi-axis F/M sensors.

Accurate Force/Moment (F/M) measurements are required in many applications, and multi-axis F/M sensors have been utilized a wide variety of robotic systems since 1970s. A multi-axis F/M sensor is capable of measuring multiple components of force terms along x-, y-, z-axis (Fx, Fy, Fz), and the moments terms about x-, y- and z-axis (Mx, My and Mz) simultaneously. In this manuscript, we describe experimental and theoretical approaches for using modular Elastic Elements (EE) to efficiently achieve multi-axis, high-performance F/M sensors. Specifically, the proposed approach employs combinations of simple modular elements (e.g. lamella and diaphragm) in monolithic constructions to develop various multi-axis F/M sensors. Models of multi-axis F/M sensors are established, and the experimental results indicate that the new approach could be widely used for development of multi-axis F/M sensors for many other different applications.