The AutoInit function of the ADMA is used to automatically set the ADMA inertial states after system start-up, including the yaw angle (Heading). This is only possible with an adequate vehicle velocity, since the yaw angle will be overwritten with the COG (GNSS Course Over Ground) value. Therefore, a certain speed is essential.
The “Min. velocity for AutoInit (m/s)”-threshold is used to allow the user to set this threshold to his application requirements. For instance, dozers and other slow-moving vehicles have difficulties to reach velocities of about 5 m/s.
Minimum velocity for heading control – threshold is used for activating the heading control. At a velocity, greater than this threshold, the yaw angle (Heading Angle) is adjusted to the direction of travel GNSS Course Over Ground (COG). This also corrects an offset in the side slip angle. At a vehicle speed below this threshold, the yaw angle is no longer controlled in the direction of travel (COG). A possible offset could assemble in the yaw angle and side slip angle (SSA) over the time.
Note: Depending on GNSS reception the accuracy can vary quite a lot at low speeds. We recommend using a 1 m/s threshold only with good GNSS reception. In case of bad GNSS reception 5 m/s are advisable, under certain conditions even 7 m/s.