Relative velocity detecting apparatus for automotive vehicle
First Claim
1. A relative velocity detecting apparatus for an automotive vehicle, comprising:
- an inter-vehicle distance detector, disposed on the vehicle so as to be oriented toward a forward detection zone of the vehicle to detect an inter-vehicle distance to a preceding vehicle which is running ahead of the vehicle, to recognize whether the preceding vehicle has entered the forward detection zone and to derive the inter-vehicle distance value lrn (n=1, 2, - - - , n) whenever a predetermined period of time has passed when recognizing that the preceding vehicle has entered the forward detection zone;
a relative velocity calculator to perform a band pass filter calculation for the inter-vehicle distance value lrn, the band pass filter being expressed as;
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Abstract
In a relative velocity detecting apparatus for an automotive vehicle applicable to an automatic vehicular velocity control system to follow up a preceding vehicle, an inter-vehicle distance detector is provided which is disposed on the vehicle so as to be oriented toward a forward detection zone of the vehicle to detect an inter-vehicle distance to the preceding vehicle which is running ahead of the vehicle, to recognize whether the preceding vehicle has entered the forward detection zone and to derive the inter-vehicle distance value lrn (n=1, 2, . . . , n) whenever a predetermined period of time has passed when recognizing that the preceding vehicle has entered the forward detection zone, a relative velocity calculator is provided to perform a band pass filter calculation for the inter-vehicle distance value lrn, the band pass filter being expressed as: CF0·S/(S2+CF1·S+CF0), wherein CF0 and CF1 denote constants, and to calculate a relative velocity value vr of the preceding vehicle to the vehicle according to the above equation, and an initial value setting section is provided to set a first initial value lr0 of the inter-vehicle distance value and a second initial value vr0 of the relative velocity value in the band pass filter calculation by the relative velocity calculator during a run of the vehicle.
26 Citations
8 Claims
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1. A relative velocity detecting apparatus for an automotive vehicle, comprising:
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an inter-vehicle distance detector, disposed on the vehicle so as to be oriented toward a forward detection zone of the vehicle to detect an inter-vehicle distance to a preceding vehicle which is running ahead of the vehicle, to recognize whether the preceding vehicle has entered the forward detection zone and to derive the inter-vehicle distance value lrn (n=1, 2, - - - , n) whenever a predetermined period of time has passed when recognizing that the preceding vehicle has entered the forward detection zone;
a relative velocity calculator to perform a band pass filter calculation for the inter-vehicle distance value lrn, the band pass filter being expressed as;
- View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A relative velocity detecting apparatus for an automotive vehicle, comprising:
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an inter-vehicle distance detector, disposed on the vehicle so as to be oriented toward a forward detection zone of the vehicle to detect an inter-vehicle distance to a preceding vehicle which is running ahead of the vehicle, to recognize whether the preceding vehicle has entered the forward detection zone and to derive the inter-vehicle distance value lrn (n=1, 2, - - - , n) whenever a predetermined period of time has passed when recognizing that the preceding vehicle has entered the forward detection zone;
a relative velocity calculator to perform a band pass filter calculation for the inter-vehicle distance value lrn, the band pass filter being expressed as;
CF0·
S/(S2+CF1·
S+CF0), wherein CF0 and CF1 denote constants and S denotes a differential operator, and to calculate a relative velocity value vr of the preceding vehicle to the vehicle according to the above equation; and
an initial value setting section to change a first initial value lr0 of the inter-vehicle distance value from null and to change a second initial value vr0 of the relative velocity value from null in the band pass filter calculation by the relative velocity calculator.
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Specification