The teacher assigned how to use the accelerometer to measure the displacement of the swinging object

phxx

The teacher assigned how to use the accelerometer to measure the displacement of the swinging object [Copy link]

 

I don't know where to start, could you guys give me some advice on what I should do, thank you

maychang

The integral of acceleration is velocity. The integral of velocity is displacement. So you need to do two integrals.

phxx

maychang posted on 2018-2-1 16:13 Acceleration integral is velocity. Velocity integral is displacement. So you need to do two integrals.

The teacher asked me to make a finished product, which specifically involved what type of sensor to use, signal processing, etc.

maychang

phxx posted on 2018-2-2 10:44 My teacher asked me to make a finished product, which specifically involved what type of sensor to use, signal processing, etc.

It is very likely that your teacher has no experience in doing this kind of work. To measure displacement, just use a displacement sensor directly. Why use an acceleration sensor and integrate it twice? The integral operation error is relatively large and troublesome.

maychang

phxx posted on 2018-2-2 10:44 My teacher asked me to make a finished product, which specifically involved what type of sensor to use, signal processing, etc.

Directly using a displacement sensor or position sensor is not only convenient, but also usually has higher accuracy. After measuring the displacement, it is also easy to get the velocity and acceleration values.

phxx

maychang posted on 2018-2-2 11:20 It is very likely that your teacher has no experience in doing this kind of work. To measure displacement, just use a displacement sensor directly. Why use acceleration...

Integration does produce errors. If there is a good algorithm, it can make up for this.

phxx

maychang posted on 2018-2-2 11:22 Directly using displacement sensors or position sensors is not only convenient, but also usually has higher accuracy. After measuring the displacement, we need to get the velocity and acceleration values...

What is measured is the displacement of the swinging object. The idea is to install an acceleration sensor on the swinging object to measure the displacement; can the displacement sensor measure the displacement of the swinging object? I don't know this yet

maychang

phxx posted on 2018-2-2 12:06 It measures the displacement of a swinging object. The idea is to install an accelerometer on the swinging object to measure the displacement; the displacement sensor can measure the...

There is no one method that is suitable for all measurements, and no one sensor is suitable for all measurements. Your multimeter can measure AC voltage. Do you use a multimeter to measure the voltage on a 500kV high-voltage transmission line? The moon is a swinging object to the earth, and the speaker cone is also a swinging object to the speaker. Without a detailed description of the test conditions and requirements, there is no way to say whether the displacement sensor can measure the displacement of a swinging object.

phxx

maychang posted on 2018-2-2 12:36 There is no one method that is suitable for all measurements, and there is no one sensor that is suitable for all measurements. Your multimeter can measure AC voltage, ...

Well, it is to measure an object with a certain length and measure its displacement in three-dimensional space

maychang

phxx posted on 2018-2-2 14:24 Well, it is to measure an object of a certain length and measure its displacement in three-dimensional space

Measuring an object of a certain length and measuring its displacement in three-dimensional space Astronomers measure the orbit of Mars, which is completely consistent with your description of "measuring an object of a certain length and measuring its displacement in three-dimensional space". Zoologists measure the migration of a whale, which is also completely consistent. Military engineers measure the trajectory of missiles, which is also completely consistent. Obviously, they use different methods and equipment.

phxx

maychang posted on 2018-2-2 14:30 To measure an object with a certain length, measure its displacement in three-dimensional space. Astronomers measure the orbit of Mars, which is completely consistent with your description "to measure an object with a certain length...

Similar to the simple pendulum experiment

maychang

phxx posted on 2018-2-2 15:37 Similar to the simple pendulum experiment

"Similar to the simple pendulum experiment" To measure the displacement of the pendulum ball, the simplest way is to measure the angle between the cycloid and the vertical direction (two-dimensional), or to measure the angle between the cycloid and the vertical direction and the angle between the projection of the cycloid on the horizontal plane and a certain direction (such as the north direction) (three-dimensional). The above method requires that the length of the cycloid is known.

maychang

phxx posted on 2018-2-2 15:37 Similar to the simple pendulum experiment

“Similar to the simple pendulum experiment” How do you solve the power supply problem for your accelerometer? The measurement results must be used by a certain device. How do you transmit the sensor measurement results to the device that uses the measurement results? Wireless transmission of power? Wireless transmission of measurement results?

phxx

maychang posted on 2018-2-2 16:08 "Similar to the simple pendulum experiment" To measure the displacement of the pendulum ball, the easiest way is to measure the angle between the pendulum line and the vertical direction (two-dimensional), or to measure the pendulum...

The length is already known. If this angle is used to calculate the displacement, then there is no need to measure the acceleration?

phxx

maychang posted on 2018-2-2 16:12 "Similar to the simple pendulum experiment" How do you solve the power supply problem of your acceleration sensor? The measurement results must be used by a certain device. How to transmit the sensor measurement results...

I am going to make a box and put these things in it. I haven't considered whether it is wired or wireless yet. I am going to transmit the data to the microcontroller

maychang

phxx posted on 2018-2-2 17:08 The length is already known. If we use this method to calculate the displacement using the angle, then there is no need to measure the acceleration?

"If we use this method to calculate the displacement using the angle, then there is no need to measure the acceleration?" Of course, there is no need to measure the acceleration. The angular displacement is differentiated to get the angular velocity, and the angular velocity is differentiated to get the angular acceleration.