机器人学基础第6章机器人传感器.ppt

《机器人学基础第6章机器人传感器.ppt》由会员分享，可在线阅读，更多相关《机器人学基础第6章机器人传感器.ppt（41页珍藏版）》请在三一办公上搜索。

1、1,中南大学蔡自兴，谢 斌zxcai,2010,机器人学基础第六章 机器人传感器,1,Ch.6 Robot Sensors,Fundamentals of Robotics,Fundamentals of Robotics,Ch.6 Robot Sensors,2,6.1 Introduction to Robot Sensors 6.2 Internal Sensors（内部传感器）6.3 External Sensors（外部传感器）6.4 Robot Sensor Application Considerations 6.5 Summary,Ch.6 Robot Sensors,6.1

2、Introduction to Robot Sensors,Application of multi-sensors in mobile robot,6.1 Introduction to Robot Sensors,Robot sensors can be divided into two main categories:Internal stateDetect position and orientation in the coordinate of the robot itself,deal with the detection of variables such as arm join

3、t position,velocity,and acceleration.External stateLocalize the robot to the environment,deal with the detection of variables such range,proximity,and touch.,6.1.1 Classification of Robot Sensors,6.1 Introduction to Robot Sensors,Most needed sensory abilities for robot:Simple Touch:detect whether th

4、e object is there or not.Compound Touch:detect the size and shape of the object.Simple Force:detect force along one direction.Compound Force:detect forces along multiple directions.Proximity:non-contact detection of objects.Simple Vision:detect feature such as holes,lines,and corners.Compound Vision

5、:recognition of object.,6.1.1 Classification of Robot Sensors,6.1 Introduction to Robot Sensors,6,6.1 Introduction to Robot Sensors 6.2 Internal Sensors（内部传感器）6.3 External Sensors（外部传感器）6.4 Robot Sensor Application Considerations 6.5 Summary,Ch.6 Robot Sensors,6.2.1 Position/Displacement Sensors 位置传

6、感器 A position sensor is any idea that permits position measurement.It can either be an absolute position sensor or a relative one(displacement sensor).Position sensors can be either linear or angular.Inductive Non-Contact Position Sensors,String Potentiometer,Linear variable differential transformer

7、(LVDT),Potentiometer,Capacitive transducer,Hall effect sensor,Proximity sensor(optical),Grating sensor,Rotary encoder(angular),Photodiode array,etc.,6.2 Internal Sensors,6.2 Internal Sensors,1.Linear Potentiometer 线性电位计 Consists of a wirewound resistor(or a thin film resistor),and a sliding contact

8、point.,6.2.1 Displacement/Position Sensors,6.2 Internal Sensors,A rotary encoder,also called a shaft encoder,is an electro-mechanical device that converts the angular position of a shaft or axle to an analog or digital code,making it an angle transducer.,2.Rotary encoder,a)导电塑料型,b)线圈型,6.2 Internal S

9、ensors,3.Electro-optical Position Sensor,a)光电位置传感器 b)感光量曲线,6.2 Internal Sensors,Find the relationship between the distance and the received light volume(shows in Fig.b)in advance,we can measure the displacement x of the light source.,1Absolute Optical Angle Sensor 光学式绝对型旋转编码器,6.2.2 Angle Sensors,6.2

10、 Internal Sensors,For example,resolution of a 12 bit encoder is 2-12=4096,so we have a resolution of 1/4096(for a round of 360 degrees).,Absolute rotary encoders can also be used to detect angular velocity.By comparing current value and stored values,we can obtain the corresponding angular velocity.

11、,1Absolute Optical Angle Sensor,6.2 Internal Sensors,Counting the number of conversions to calculate relative angle.,Incremental rotary encoder can only measure relative angle from initial value to current one.Therefore,in order to know the exact current angle value,some other methods(such as the ab

12、solute encoder)are needed to identify the initial value of angle.,2Relative Angle Sensor 光学式增量型旋转编码器,6.2 Internal Sensors,In this approach,no matter the clockwise(CW)rotation,or counter-clockwise(CCW)rotation,output of the sensing light always alternate between H and L,so we can not get the directio

13、n of rotation.,2Relative Angle Sensor,6.2 Internal Sensors,Adding another sensor(B)1/4 cycle away from sensor A.Typically,when clockwise(CW)rotation,signal A changes before B,vice versa.,2Relative Angle Sensor,6.2 Internal Sensors,Attitude sensors are used to detect the relative relationship between

14、 the robot and ground.When the robot is fixed(just as the majority of industrial robot),there is no need to install such sensors.Attitude sensors are essential for mobile robots.Attitude sensors detect moving changes in position and orientation of the robot that can be used to control the robot impl

15、ement desired instruction.,6.2.3 Attitude Sensors 姿态传感器,6.2 Internal Sensors,A gyroscope is a device for measuring or maintaining orientation,based on the principles of conservation of angular momentum.,1电动机2角度传感器3转子4一弹簧,Shown right is a rate gyro.,1Gyro Sensor 陀螺仪,6.2 Internal Sensors,gas rate gyro

16、scope气体速率陀螺仪optical gyroscope光陀螺仪piezoelectric vibratory gyroscope压电振动式陀螺(shown on the right),2Other Gyros,6.2 Internal Sensors,19,6.1 Introduction to Robot Sensors 6.2 Internal Sensors（内部传感器）6.3 External Sensors（外部传感器）6.4 Robot Sensor Application Considerations 6.5 Summary,Ch.6 Robot Sensors,6.3.1

17、Tactile Sensors 触觉传感器The prototype of robot tactile sensor is an imitation of human tactile sense of touch functions:Tactile sensePressure senseSlip senseForce sense,6.3 External Sensors 内传感器,6.3 External Sensors,1Touch Sensor 接触觉传感器,Application:Touch sensors are equipped in the palm of the end-effc

18、tor in order to grip objects precisely.,6.3 External Sensors,Robot pressure sensor can detect the pressure and its distribution through an array of piezoelectric elements.(Eg.Springs(弹簧)for mechanical detecting).,2Pressure Sensor 压觉传感器,Applications:By smart control of pressure,end-effector can pick

19、up not only fragile objects as glass cups,but also soft object as tofu and eggs.,6.3 External Sensors,Slip sensor is used to detect force and displacement in the vertical direction of the pressure.,3Slip Sensor 滑觉传感器,6.3 External Sensors,Robot Force sensors can be divided into 3 categories:Joint for

20、ce sensor,installed in the joint actuator,measure the output force and torque of the actuator itself,is used to control the feedback of the force.Wrist force sensor,mounted between the end-effector and the last joint,measure forces and torques on the end-effector for all directions.Finger force sens

21、or,installed in the robot finger joints,measure the clamping force of an object.,4Force Sensor 力觉传感器,6.3 External Sensors,Draper实验室研制的六维腕力传感器,SRI（Stanford Research Institute）研制的六维腕力传感器,林纯一研制的腕力传感器,4Force Sensor,6.3 External Sensors,6.3.2 Distance Sensor 机器人距离传感器,1 Ultrasonic Distance Sensor 超声波距离传感器

22、 Ultrasonic distance sensor is consisting of a transmitter and a receiver,which are both based on piezoelectric effect(压电效应).,6.3 External Sensors,Principles of Ultrasonic Ranging-TOF(Time Of Flight，时间行程法),超声波测距原理图,1Ultrasonic Distance Sensor,6.3 External Sensors,1Ultrasonic Distance Sensor,6.3 Exte

23、rnal Sensors,2Proximity Sensors 接近觉传感器,A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact.A proximity sensor often emits an electromagnetic or electrostatic field,or a beam of electromagnetic radiation(infrared,for instance),and looks for change

24、s in the field or return signal.The object being sensed is often referred to as the proximity sensors target.,6.3 External Sensors,Different proximity sensor targets demand different sensors.For example,a capacitive or photoelectric sensor might be suitable for a plastic target;an inductive proximit

25、y sensor requires a metal target.,2Proximity Sensors,6.3 External Sensors,Research have shown that the visual perception of information accounts for 80%of what people perceived from outside world.Cells of human vision have the magnitude of about 108,is 3000 times to auditory cells(听觉),and over 100 t

26、imes to the sensory cells of the skin（皮肤触觉）.,6.3.3 Vision Sensors 视觉传感器,6.3 External Sensors,Charge-coupled device(CCD)is a major technology for digital imaging.Although CCDs are not the only technology to allow for light detection,CCDs are widely used in professional,medical,and scientific applicat

27、ions where high-quality image data is required.,CCD(Charge-Coupled Device)Sensors,6.3 External Sensors,A total of 256 gray scale,from the Figure(a)to(f)followed by resolution of 512 512,256 256,128 128,64 64,32 32,16 16.,The impact of change on the image resolution,6.3 External Sensors,Figure(a)to(f

28、)with resolution of 512 512,followed by 256,64,16,8,4,and 2 gray levels.,The impact of change on the image gray,6.3 External Sensors,Figure(a)to(f)followed by:256 256,128-level gray scale;181 181,64-level gray scale;128 128,32-level gray scale;90 90,16-level gray scale;64 64,8-level gray scale;45 45

29、,4-level gray scale.,The impact of changes in both resolution and grayscale,6.3 External Sensors,36,6.1 Introduction to Robot Sensors 6.2 Internal Sensors（内部传感器）6.3 External Sensors（外部传感器）6.4 Robot Sensor Application Considerations 6.5 Summary,Ch.6 Robot Sensors,6.4 Considerations in Robot Sensor Ap

30、plication 机器人传感器应用中考虑的问题,High precision,good repeatabilityGood stability,high reliabilityStrong anti-interference abilityLight weight,small size,easy installationCheap,6.4 Robot Sensor Application Considerations,38,6.1 Introduction to Robot Sensors 6.2 Internal Sensors（内部传感器）6.3 External Sensors（外部传

31、感器）6.4 Robot Sensor Application Considerations 6.5 Summary,Ch.6 Robot Sensors,6.5 Summary 小结,传感机器人是通过各种传感器或传感系统，向机器人提供感觉的装置，如视觉、听觉、触觉、力觉、嗅觉等。这种智能机器人的智能是由传感器提供的。首先阐述机器人传感器的特点与分类，涉及机器人的感觉顺序与策略、机器人传感器的分类以及应用传感器时应考虑的问题。接着分别讨论机器人的内传感器和外传感器。在内传感器部分，研究了位移/位置传感器、速度和加速度传感器及力觉传感器等。,6.5 Summary 小结,在外传感器部分，研究了触觉传感器、应力觉传感器、接近度传感器和其他外传感器。最后，举例介绍了一些有代表性的机器人视觉装置，包括机器人眼、视频信号数字变换器和固态视觉装置等。对于各种传感器，着重讨论它们的工作原理，并说明了应用在应该注意的问题。,Thank youFor Attention!,Fundamentals of Robotics,41,