摘要 |
Method and apparatus of operation for (motor vehicle) cruise control system, using driver input to request reduction in vehicle speed and an output for causing a gearbox downshift, method comprising detecting repeated / prolonged activation of the input, and causing transmission downshift in response. Repeat activations may be at a frequency greater than 2Hz, or may exceed a threshold of four. Prolonged activation may exceed two seconds. Vehicle speed input may enable / disable method by detecting a travel above / below pre-set cruise speed. Engine fuelling input may enable / disable method by detecting cessation in / continued engine fuelling. Gradient input may enable / disable method by detecting negative / non-negative road gradient. Output may cause downshift of two or more sequential speed ratios. Engine speed may be used, via algorithm or look-up table, to calculate available engine breaking for potential downshifts / upshifts, appropriate downshift / upshift being chosen to provide desired deceleration or to maintain desired cruise speed. |