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NAO NEX GEN HUMANOID ROBOT- PROJECT :: CENSORS

NAO NEX GEN HUMANOID ROBOT- PROJECT :: CENSORS

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  • 1. NAO NEX GEN ROBOT RAKESH KUMAR ISHA AGARWAL SANJAY KALKARE PRIYA NEHA. B Sensors (v.1c) 1
  • 2. CENG4480_A1 SensorsSensing the real world Sensors (v.1c) 2
  • 3. Sensors Motion (Orientation/inclination )sensors Force/pressure/strain Position Temperature and humidity Rotary position Light and magnetic field sensors Sensors (v.1c) 3
  • 4. Motion (Orientation/inclinationsensors Acceleration Gyroscope Compass Tilt Sensor Sensors (v.1c) 4
  • 5. Accelerometer Functions: measure acceleration in one or more directions, position can be deduced by integration. Orientation sensing : tilt sensor Vibration sensing Methods: Mass spring method ADXL78 (from Analog Device ) Air pocket method (MX2125) Sensors (v.1c) 5
  • 6. ADXL78 (from Analog Devicehttp://www.analog.com/UploadedFiles/Data_Sheets/ADXL ) Mass spring type (output acceleration in G) Measure the capacitance to create output Sensors (v.1c) 6
  • 7. ADXL330 accelerometer for three (X,Y,Z ) directionshttp://www.analog.com/UploadedFiles/Data_Sheets/ADXL330.pdf 3D Sensors (v.1c) 7
  • 8. 2D translational accelerometerMX2125 Gas pocket type When the sensor moves, the temperatures of the 4 sensors are used to evaluate the 2D accelerations Sensors (v.1c) 8
  • 9. Accelerometer demo:orientation sensing Self-balance Robot Sensor demo Sensors (v.1c) 9
  • 10. Accelerometer demo :Tilt sensing demo Tilt sensing demo Sensors (v.1c) 10
  • 11. Gyroscopes Gyroscope Measure rotational angle Rate Gyroscope Gyroscope measure the rate of rotation along 3-axes of X (pitch), Y (roll), and Z (yaw). Modern implementations are using Microelectromechanical systems (MEMS) technologies. Sensors (v.1c) 11
  • 12. Gyroscope to measure Rational acceleration ADXRS401FEATURES Complete rate gyroscope on a single chip Microelectromechanical systems (MEMS) Z-axis (yaw-rate) responseAPPLICATIONS GPS navigation systems Image stabilization Inertial measurement units Platform stabilization Sensors (v.1c) 12
  • 13. Compass-- the Philips KMZ51magnetic field sensor 50/60Hz (high) operation, a jitter of around 1.5° Sensors (v.1c) 13
  • 14. Rate gyroscope demoUsing Gyroscope compass for virtual reality application in an iphone Sensors (v.1c) 14
  • 15. Application of motion sensorsSelf balancing robot by Kelvin Ko Motion sensors: http://hk.youtube.com/watch?v=2u-EO2FDFG0 gyroscope and accelerometer 20cm 35cm Sensors (v.1c) 15
  • 16. Complementary filter Since Combine two sensors to find output Sensors (v.1c) 16 16
  • 17. Complementary filterθ=rotation angle, τ=filter time constant, s=laplaceoperatorhttp://en.wikipedia.org/wiki/Low-pass_filter Sensors (v.1c) 17 17
  • 18. Self Balanced robot usingcomplementary filter Sensors (v.1c) 18 18
  • 19. Tilt Sensor by OMRON Detect tilting 35 ~ 65 degrees in right-and- left inclination Sensors (v.1c) 19
  • 20. Force/pressure/strain Force-sensitive resistor (FSR) Strain gauge Flexion Air pressure Sensors (v.1c) 20
  • 21. Force Sensing Resistors FSR402 Sensors (v.1c) 21
  • 22. Force Sensing Resistor Demo Sensors (v.1c) 22
  • 23. Application for a walking robot Walking robot Sensors (v.1c) 23
  • 24. Application of force sensing resistancesensors to balance a walking robot Balancing Floor tilled left Floor tilled rightNeutral position upper leg bend right upper leg bend left Four sensors under the foot Sensors (v.1c) 24
  • 25. Four Force sensors under the foot D Sensors (v.1c) 25
  • 26. The Nao robot uses force feedback at its feet Sensors (v.1c) 26
  • 27. Strain Gauge : Force sensors Piezoelectric crystal: produces a voltage that is proportional to force applied Strain gauge: cemented on a rod. One end of the rod is fixed, force is applied to the other end. The resistance of the gauge will change with the force. Sensors (v.1c) 27
  • 28. Single element strain gauge sensitive to temperature change. Vb gauge R Gauge=R+∆R rod V0 R R load  R R   ∆R   ∆R   G ∆L V0 = Vb  −  = Vb   ≈ Vb  = Vb   2 R 2 R + ∆R   4 R + 2 ∆R   4R   4 L  ∆R ∆Lfor =G and G = strain gauge factor, L = length of the gauge R LR = unstrained gauge resistance Sensors (v.1c) 28
  • 29. Four-element (Wheatstonebridge) strain gauge sensor, Four times more sensitive than single gauge system; not sensitive to temperature change. All gauges have unstrained resistance R. t1 t2 Vb b2=R-∆R t1=R+∆R rod V0 b1 b2 t2=R+ ∆R b1=R-∆R load  R + ∆R R − ∆R   2∆ R   ∆L V0 = Vb  −  = Vb   = Vb  G   R + ∆R + R − ∆R R + ∆R + R − ∆R   2R   L  Sensors (v.1c) 29
  • 30. Flexion (bend) sensors resistance: 10 KΩ (0°); 30-40 KΩ (90°) / Sensors (v.1c) 30
  • 31. Felixon resistance Demo Sensors (v.1c) 31
  • 32. Air pressure sensor Measure up to 150 psi (pressure per square inch ). Sensors (v.1c) 32
  • 33. Position sensors Infra-red range sensor Linear and Rotary position sensors Sensors (v.1c) 33
  • 34. Infra-red Range detectors by SHARP (4 to 30cm) An emitter sends out light pulses. A small linear CCD array receives reflected light. The distance corresponds to the triangle formed. Sensors (v.1c) 34
  • 35. IR radar using the Sharp rangedetector Sensors (v.1c) 35
  • 36. Position sensors, from[1] Rotary Linear Optical shaft encoder Sensors (v.1c) 36
  • 37. Magnetic rotary encoder) non touch sensing Sensors (v.1c) 37
  • 38. Optical rotary encoder) The light received (on or off) will tell the rotation angle) 3 light receivers Light paths Rotation shaft 3 light emitters Crank shaft sensor Sensors (v.1c) 38 http://www.youtube.com/watch?v=RuIislTGOwA
  • 39. Temperature and humidity Temperature humidity Sensors (v.1c) 39
  • 40. Temperature sensorsLM135/235/335 features(from NS) Directly calibrated in °Kelvin 1°C initial accuracy available Operates from 400 µA to 5 mA Less than 1 Ohm dynamic impedance Easily calibrated Wide operating temperature range 200°C over range Low cost Sensors (v.1c) 40
  • 41. Application note (connecting to anADC e.g. ADC0820 or ADC0801) Sensors (v.1c) 41
  • 42. Capacitive Atmospheric HumiditySensor BCcomponents 2322 691 90001 10-90%RH Dc Sensors (v.1c) 42
  • 43. Leaf Sensor Alerts When PlantsAre Thirsty Sensors (v.1c) 43
  • 44. TSL250, TSL251, TSL252LIGHT-TO-VOLTAGE OPTICAL SENSORS Light-to-voltage optical sensors, each combining a photodiode and an amplifier (feedback resistor = 16 MW, 8 MW, and 2 MW respectively). The output voltage is directly proportional to the light intensity on the photodiode. Sensors (v.1c) 44
  • 45. Cadmium Sulfoselenide (CdS)Photoconductive Photocells Light sensing using CdS Sensors (v.1c) 45
  • 46. Hall effect Sensors for sensingmagnetic flux“B field”, see: Sensors (v.1c) 46
  • 47. Application on Magnetic levitation 磁懸浮 Magnetic levitation Train Model 磁懸浮火車 frog levitation Sensors (v.1c) 47
  • 48. Hall effect sensors and brushless DCmotors Brushless DC motor Is it using Hall effect sensor? Dont known. Sensors (v.1c) 48
  • 49. Novel sensors Kinect / Sensors (v.1c) 49
  • 50. Many KINECTDIY projects Sensors (v.1c) 50
  • 51. Control systemsExample: A temperature control system Sensors (v.1c) 51
  • 52. Control example: Temperature control system computer Digital control TimerWater tank circuit Temp. Sample Sensor Instrum. A/D amp. & Hold CPU Pulse Width Heater modulation D/A & solid state relay Sensors (v.1c) 52
  • 53. Temperature control method 1: ON-Off (bang-bang)control (poor) Easy to implement, bad control result -- contains overshoot undershot. Algorithm for on-off-control: Loop forever: If (Tfrom_sensor > Treq required temperature) then (heater off ) else (heater on). Overshoot Treq Steady state error UndershootTemp On-off control result Time Sensors (v.1c) 53
  • 54. Temperature control method 2 : Proportional-integral-differential (PID) temperature control (good) Init. (set required temperature Treq) Loop forever{ get temperature T from sensor, Tw e=T - Treq then Tw =e*G*{Kp+Kd*[d(e)/dt] +Ki*∫e dt } Proportional, differential, integral else } //G,Kp,Kd,Ki can be adjusted by user Sensors (v.1c) 54 Tw
  • 55. PID block diagram Kd Kp Figure 1 - Parallel PID block diagram Ki Sensors (v.1c) 55
  • 56. PID control using pulse widthmodulation PWM Tw (depends on e ) Time Fixed period and fixed number of pulsesTemperature On-off control: oscillates and unstableTreq PID control result of method 2 Time Sensors (v.1c) 56
  • 57. Summary Studied the characteristics of various sensors and their applications Sensors (v.1c) 57