LSM6DSV16X pitch / roll angle heavily influenced by longitudinal / lateral acceleration

[Shuai]

Hello ST Community,

Test Environment

HW:

STEVAL-MKI227KA

STEVAL-MKI109V3

 

SW:

Unico-GUI or MEMS-Studio

 

Phenomenon

The pitch/roll angle generated by LSM6DSV16X SFLP is heavily influenced by longitudinal / lateral acceleration. E.g., if I mount the MEMS board in a car, the pitch angle can varied more than ±15° while the car is accelerating or decelerating. The problem is quite similar with this post: Solved: Re: Seeking Assistance: Overcoming Linear Accelera... - STMicroelectronics Community I tried adjusting the ODR and FS parameters but it didn't help. Disabling the gyro will make the situation even worse (pitch angle varied more than ±30°).

 

Analysis

My goal is to measure the pitch / roll angle on a moving vehicle. However, the sensor fusion output of LSM6DSV16X SFLP does not seem to be able to support this kind of dynamic inclinometer application. And I do not know whether and how can I adjust SFLP configurations to make the algorithm rely more on the gyro instead of acc.

 

Questions

1. LSM6DSV16X spec shows it has 1.6deg pitch angle accuracy in high dynamic situations. Does my application fits in this scenario? And why is the error violates the spec so much?
2. As mentioned, are there any configurations of SFLP to support this dynamic inclinometer application?
3. I noticed there is a MotionDI library in X-CUBE-MEMS1 SW package. But I did not find it in MEMS-Studio (while other MotionXX libs are in it). Will MotionDI library solve my problem? And can I try this lib on my HW (STEVAL-MKI227KA + STEVAL-MKI109V3)? It seems running this lib will require STM32 Nucleo board.
4. Generally, are there any documents like user guide or application note to help me understand how to configure my IMU for my applications?

 

Thanks in advance!

[Federica Bossi]

Hi @Shuai ,

Using MEMS_Studio in default mode (in the quick setup page), only allows the inclinometer to use accelerometer data only, that in dynamic situations can leads to inaccurate angle estimation.

Instead by selecting the sensor fusion mode, when using the inclinometer application, gyroscope data are also used, in order to obtain a more accurate pitch and roll angle estimation.

[Shuai]

Hi Federica,

 

Thanks for your reply.

I understand that I should apply sensor fusion mode in this inclinometer application (especially in dynamic scenarios). The problem is the error is still too large in sensor fusion mode. I suppose the SFLP can be somehow configured for this scenario but I've no idea how to do it.

 

Shuai

[Federica Bossi]

Hi @Shuai ,

Are you using the latest version of MEMS Studio? If not, can you please try again with it?