초록 ▼

In a vehicle suspension control in which the output of a vehicle body mounted absolute vertical acceleration sensor is integrated to provide an absolute vertical velocity signal, the sensor output is high pass filtered to remove DC components but pass components in the frequency range 1-2 Hz. The fi

In a vehicle suspension control in which the output of a vehicle body mounted absolute vertical acceleration sensor is integrated to provide an absolute vertical velocity signal, the sensor output is high pass filtered to remove DC components but pass components in the frequency range 1-2 Hz. The filter comprises a second order digital all-pass filter embodied recursively on a 16 bit, fixed point, digital signal processor (DSP). A first stage normalized lattice two-pair network reduces to a unity gain stage; and a second stage single multiplier two-pair lattice network minimizes computational time. The 32 bit internal accumulators of the 16 bit DSP are used advantageously to prevent errors due to internal overflow of the recursive variable.

대표청구항 ▼

A motor vehicle comprising, in combination: a body; a wheel; a suspension actuator connected between the body and wheel; an accelerometer on the vehicle body for providing a vehicle vertical body acceleration signal; a high-pass filter comprising a 16 bit, fixed point, digital signal processor with

A motor vehicle comprising, in combination: a body; a wheel; a suspension actuator connected between the body and wheel; an accelerometer on the vehicle body for providing a vehicle vertical body acceleration signal; a high-pass filter comprising a 16 bit, fixed point, digital signal processor with a 32 bit accumulator and a loop time of no more than 1 millisecond, the signal processor being configured as a second order all-pass digital filter having a phase shift center at zero Hz and a phase shift bandwidth of 0.1 Hz, in combination with means for summing the output of the second order all pass digital filter with the vertical body acceleration signal and reducing the sum thereof by a factor of one half, the high pass filter being effective to suppress components of the vehicle vertical body acceleration signal at zero Hz but pass a filtered vehicle body acceleration signal comprising components of the vehicle vertical body acceleration signal above 1 Hz; an integrator for integrating the filtered vehicle vertical body acceleration signal to produce a vehicle vertical body velocity signal; and apparatus responsive to the vehicle vertical body velocity signal to control the suspension actuator in real time.