Document ID: chunk:federal_register_of_legislation:F2018C00341:body:0:p40
Version: federal_register_of_legislation:F2018C00341
Segment Type: other
Provision Reference: 
Character Range: 115204–118177

zeroed to remove sensor offset utilizing static pre-test data.  The lateral acceleration data at the vehicle centre of gravity is determined by removing the effects caused by vehicle body roll and by correcting for sensor placement via the use of coordinate transformation.  For data collection, the lateral accelerometer shall be located as close as possible to the position of the vehicle's longitudinal and lateral centres of gravity.

       5.11.4. Steering wheel velocity is determined by differentiating the filtered steering wheel angle data.  The steering wheel velocity data is then filtered with a moving 0.1 second running average filter.

       5.11.5. Lateral acceleration, yaw rate and steering wheel angle data channels are zeroed utilizing a defined "zeroing range."  The methods used to establish the zeroing range are defined in paragraphs 5.11.5.1. and 5.11.5.2.

       5.11.5.1. Using the steering wheel rate data calculated using the methods described in paragraph 5.11.4., the first instant that the steering wheel rate exceeds 75 deg/sec is identified.  From this point, steering wheel rate shall remain greater than 75 deg/sec for at least 200 ms.  If the second condition is not met, the next instant that the steering wheel rate exceeds 75 deg/sec is identified and the 200 ms validity check applied.  This iterative process continues until both conditions are ultimately satisfied.

       5.11.5.2. The "zeroing range" is defined as the 1.0 second time period prior to the instant the steering wheel rate exceeds 75 deg/sec (i.e., the instant the steering wheel velocity exceeds 75 deg/sec defines the end of the "zeroing range").

       5.11.6. The Beginning of Steer (BOS) is defined as the first instance when the filtered and zeroed steering wheel angle data reaches -5 degrees (when the initial steering input is anticlockwise) or +5 degrees (when the initial steering input is clockwise) after a time defining the end of the "zeroing range."  The value for time at the BOS is interpolated.

       5.11.7. The Completion of Steer (COS) is defined as the time the steering wheel angle returns to zero at the completion of the Sine with Dwell steering manoeuvre.  The value for time at the zero degree steering wheel angle is interpolated.

       5.11.8. The second peak yaw rate is defined as the first local yaw rate peak produced by the reversal of the steering wheel.  The yaw rates at 1.000 and 1.750 seconds after COS are determined by interpolation.

       5.11.9. Determine lateral velocity by integrating corrected, filtered and zeroed lateral acceleration data.  Zero lateral velocity at the BOS point.  Determine lateral displacement by integrating zeroed lateral velocity.  Zero lateral displacement at the BOS point.  The lateral displacement measurement is made at 1.07 seconds after BOS point and is determined by interpolation.

       B. Requirements for BRAKE assist systems

 1.                              GENERAL