# Revision history [back]

Just to verify, is below what you are seeing when

rxplot /atlas/imu/linear_acceleration/z


Just It's an error inherent in the existing LCP solver given performance requirements. You can run simulation slower to verify, is get better results. For example, figure below what you are seeing whenfrom running:

roslaunch atlas_utils atlas.launch
rxplot /atlas/imu/linear_acceleration/z


If you increase physics->solver->iterations from default of 40 to 80, the oscillation magnitude decreases (the spike is just an artifact of parameter update):

Setting iterations to 500 reduces oscillation magnitudes even further:

It's an error inherent in the existing LCP solver given performance requirements. You can run simulation slower to get better results. For example, figure below from running:

roslaunch atlas_utils atlas.launch
rxplot /atlas/imu/linear_acceleration/z


If you increase physics->solver->iterations from default of 40 to 80, the oscillation magnitude decreases (the spike is just an artifact of parameter update):

Setting iterations to 500 reduces oscillation magnitudes even further:

Alternatively, you can low pass filter the data. As an extremely crude example, exponential filter where

accel(new) = (1 - e) * accel(new) + e * accel(old)


where e = 0.9 leads to: