Document ID: chunk:federal_register_of_legislation:F2017L01221:body:0:p13
Version: federal_register_of_legislation:F2017L01221
Segment Type: other
Provision Reference: 
Character Range: 34505–37293

Only data recorded at speeds above 15 km/h shall be taken for the calculations described in the following paragraphs.
1.5. For the determination of aABS and FABS, a low pass filter of 2 Hz for vehicle deceleration as well as pedal force shall be applied.
1.6. The five individual "deceleration versus brake pedal force" curves are averaged by calculating the mean deceleration of the five individual "deceleration vs. brake pedal force" curves at increments of 1 N pedal force. The result is the mean deceleration versus brake pedal force curve, which will be referred to as the "maF curve" in this annex.
1.7. The maximum value for the vehicle deceleration is determined from the "maF curve" and is named as "amax".
1.8. All values of the "maF curve" that are above 90 per cent of this deceleration value "amax" are averaged. This value of "a" is the deceleration "aABS" referred to in this Regulation.
1.9. The minimum force on the pedal (FABS) sufficient to achieve the deceleration aABS is defined as the value of F corresponding to a= aABS on the maF curve.
Annex 4
  Data processing for the BAS
(see paragraph 7.2.3. of this Regulation)
1. Analogue data processing
 The bandwidth of the entire, combined transducer/recording system shall be no less than 30 Hz.
 In order to execute the necessary filtering of signals, low-pass filters with order 4 or higher shall be employed. The width of the pass band (from 0 Hz to frequency fo at ‑3 dB) shall not be less than 30 Hz. Amplitude errors shall be less than ±0.5 per cent in the relevant frequency range of 0 Hz to 30 Hz. All analogue signals shall be processed with filters having sufficiently similar phase characteristics to ensure that time delay differences due to filtering lie within the required accuracy for time measurement.
 Note: During analogue filtering of signals with different frequency contents, phase shifts can occur. Therefore, a data processing method, as described in paragraph 2. of this appendix, is preferable.
2. Digital data processing
2.1. General consideration
 Preparation of analogue signals includes consideration of filter amplitude attenuation and sampling rate to avoid aliasing errors, and filter phase lags and time delays. Sampling and digitizing considerations include pre-sampling amplification of signals to minimize digitizing errors; number of bits per sample; number of samples per cycle; sample and hold amplifiers; and time-wise spacing of samples. Considerations for additional phaseless digital filtering include selection of pass bands and stop bands and the attenuation and allowable ripple in each; and correction of filter phase lags. Each of these factors shall be considered in order to achieve a relative overall data acquisition accuracy of ±0.5 per cent.
2.2. Aliasing errors