| Miniaturization is one of the main development directions of force sensor.Miniaturized multi-dimension force sensors play important roles both in space robot teleoperation and experiments on land in aeronautics and astronautics areas.Miniaturized six-axis force/torque sensor,which is installed on the wrist of miniaturized space manipulator,is the key component to help the manipulator get space force information,realize force control and guarantee safe teleoperation.Miniaturized force sensor,which is used to measure internal force of extendable rod of solar array's stretchable mechanism in space station,is expecially essential to force control of folding process of large space structures.Based on the application background and technique targets of two sensors,the article introduces the design of sensors' measurement element,hardware circuit and data acquisition circuit.Through static calibration and precision analysis,two sensors meet the design requirements.The first step of the development of miniaturized six-axis force sensor is using finite-element method of ANSYS software to make structural static analysis of the different size of sensor elastic body's structure.After several analysises and optimizations,the final structure and size are confirmed as well as their rationality evaluation.Afterwards,assembling parts are designed.The second step is to design and develop the hardware system of miniaturized six-axis force sensor including miniaturized two-stage signal amplification circuit which can be fixed in the base and data acquisition circuit based on USB serial port.To evaluate the sensor's static characteristics,several novel components for calibration are designed to improve the prescision of experiments.Researches on static decoupling algorithms based on least-square method and genetic algorithm are carried out.Using two algorithms to decouply the experimental data of static calibration separately and making error analysis along with comparison in order to choose optimal algorithm to improve the sensor's precision after decoupling.Finally,the article manufactures a sensor for extendable rod internal force measurement.The sensor reduces the undesirable effects from disturbing internal force and improves sensor accuracy through differential compensation of parallel structure from two S-type sensor of sensor measurement unit.The zero adjustment function of amplifier and the compassion on line eliminate the zero error of voltage,which achieves measurement with high-precision,easy operation,non-destruction and high universial property.At last,sensor measure accuracy is verified by calibration and test experiments.Two kinds of force sensors have been used in Perceptual Robot System and internal force measurement of extendable rod of large extension mechanism separately with good results. |
PDF Full Text Request