# How to find acceleration(rate of change in velocity) using MPU 6050?

How to find acceleration(rate of change in velocity) using MPU 6050?.MPU 6050 gives acceleration w.r.t gravitational force but how to convert it in acceleration(rate of change in velocity)?

Acceleration is the rate of change of velocity, regardless of whether the acceleration is produced by gravity or any other force. If you are referring to "g" as a unit of measurement, g = 9.8 meters/(second squared).

if the body is in horizontal position not moving it will still read 1g.I am also unable to find zero g value of imu 6050.

OK, I see what is confusing.

An accelerometer measures the difference in forces applied to the accelerometer package versus the force applied to the sensing element inside the package. Think of the accelerometer as behaving like your hand, suspending a spring connected to a weight. Your hand has to supply 1 g to the spring, so that the weight doesn't fall. Yet nothing is moving.

The accelerometer reads 1 g when while remaining still on a table, because there is a force of 1 g on the accelerometer, produced by the table to counteract the force of 1 g produced by gravity on everything. If the accelerometer is freely falling, it will read 0 g. We tend to forget that the force of gravity acts on everything, all the time.

jremington:
OK, I see what is confusing.

An accelerometer measures the difference in forces applied to the accelerometer package versus the force applied to the sensing element inside the package. Think of the accelerometer as behaving like your hand, suspending a spring connected to a weight. Your hand has to supply 1 g to the spring, so that the weight doesn't fall. Yet nothing is moving.

The accelerometer reads 1 g when while remaining still on a table, because there is a force of 1 g on the accelerometer, produced by the table to counteract the force of 1 g produced by gravity on everything. If the accelerometer is freely falling, it will read 0 g. We tend to forget that the force of gravity acts on everything, all the time.

but i want to find rate of change of velocity which will be 0 on uniform velocity or body in rest,

I don't understand your last comment.

jremington:
I don't understand your last comment.

I want to find acceleration which will be 0 while body in rest or moving with uniform speed.

You would have to be in outer space, very far from the gravitational influence of massive objects.

what is the zero g offset of mpu 6050

The zero g offset is very difficult to measure on Earth. However, there almost certainly is a constant offset on each axis, and this can be estimated by measuring the force of gravity with the accelerometer not moving, flat on the table, then flipping it over and repeating the measurement. If these measurements are not equal, then there is an offset along that axis. You probably also need to adjust the gains so that all axes read 1 g, in every orientation. This is called "calibration".

There are lots of web sites that explain how to do this for accelerometers and also for magnetometers. Here is one:

Here is the best method (in my opinion); described for magnetometers but the procedure also works for accelerometers. Sailboat Instruments: Improved magnetometer calibration (Part 1)

It depends on the context.

If you want to measure the acceleration in your car, for example, and you assume that you won't be rolling the car over, then put the accerometer in the car with the z axis pointing up or down, you will always have 1g of gravity in that direction, and then just use the x and/or y direction of the accelerometer to measure the acceleration of the car.

According to wiki accelerometer measure proper acceleration.So how to convert it in linear acceleration?

What is the difference between "proper" acceleration and "linear" acceleration?

jremington:
What is the difference between "proper" acceleration and "linear" acceleration?

proper acc=F=MA and linear acc=DV/DT.

Wrong. F = force, which is mass times acceleration.

Force is measured in Newtons = kg m /s^2, acceleration is measured in m/s^2