1. 感測器原理與應用

2. 超音波感測器 Ultrasonic Sensor Proximity sensor
A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact.
Ultrasonic sensors (also known as transceivers when they both send and receive) work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor. Sensors calculate the time interval between sending the signal and receiving the echo to determine the distance to an object.

3. 超音波感測器 Ultrasonic Sensor
Ultrasound is an oscillating sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from 'normal' (audible) sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is approximately 20 kHz (20,000 hertz) in healthy, young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz(GHz).

4. 超音波感測器 Ultrasonic Sensor
Principle of flaw detection with ultrasound. A void in the solid material reflects some energy back to the transducer, which is detected and displayed.

5. 超音波感測器
Ultrasonic Sensor
Principle of an active sonar

6. 超音波感測器 Ultrasonic Sensor
Ultrasound can be used for medical imaging, detection, measurement and cleaning. At higher power levels, ultrasonics is useful for changing the chemical properties of substances.

7. 超音波感測器 Ultrasonic Sensor
The approximate speed of sound in dry (0% humidity) air, in meters per second (m·s−1), at temperatures near 0 °C, can be calculated from:
where   is the temperature
in degrees Celsius (°C).

8. 超音波感測器
Ultrasonic Sensor

9. 超音波感測器 Ultrasonic Sensor
Sound field of a non focusing 4 MHz ultrasonic transducer with a near field length of N = 67 mm in water. The plot shows the sound pressure at a logarithmic db-scale.
Sound pressure field of the same ultrasonic transducer (4 MHz, N = 67 mm) with the transducer surface having a spherical curvature with the curvature radius R = 30 mm

10. 超音波感測器 Grove - Ultrasonic Ranger

11. 加速度感測器
Accelerometer
An accelerometer is a device that measures proper acceleration.
F=ma
In physics, acceleration is the rate at which the velocity of a body changes with time.

12. 加速度感測器
Accelerometer

13. 角速度感測器(陀螺儀) 3-Axis Digital Gyro (Gyroscope)
A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum.
In physics, angular momentum, moment of momentum, or rotational momentum is a vector quantity that represents the product of a body's rotational inertia and rotational velocity about a particular axis.
ω ：angular velocity

14. 角速度感測器(陀螺儀) Conservation of angular momentum
The law of conservation of angular momentum states that when no external torque acts on an object or a closed system of objects, no change of angular momentum can occur. 

15. 角速度感測器(陀螺儀) 3-Axis Digital Gyro (Gyroscope)

16. 角速度感測器(陀螺儀) 3-Axis Digital Gyro (Gyroscope)
Grove - 3-Axis Digital Gyro module based on ITG It is the world’s first single-chip, digital-output, 3-axis MEMS motion processing gyro optimized for gaming, 3D mice, and motion-based remote control applications for Internet connected Digital TVs and Set Top Boxes. 應用
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