Method and system for automatically detecting a preceding vehicle
First Claim
1. Apparatus for controlling the speed of a controlled vehicle to maintain a predetermined distance to a preceding vehicle identified as a target vehicle comprising:
- (a) means for determining the speed of said controlled vehicle,(b) a control vehicle speed adjustment mechanism responsive to a control signal for controlling the speed of said controlled vehicle,(c) transmitter means for generating transmitted waves toward a predetermined region preceding said controlled vehicle,(d) means for receiving waves reflected from objects in said predetermined region,(e) said predetermined region divided into at least a first and second adjacent regions and at least one of (1) said transmitter means transmitting separately defined transmitting waves into each of said first and second adjacent regions and (2) said receiver means having at least first and second aperture characteristics so as to distinguish waves reflected from each of said first and second adjacent regions,(f) means, operative when said preceding vehicle is in said first region, for periodically calculating a distance between said preceding vehicle and said controlled vehicle based on a measured travel time between the generation of said transmitted waves and the receipt, in said receiving means, of said reflected waves, said distance defined by l1i for the most recent calculation at time ti and l1i-1 for the immediately preceding calculation at time ti-1,(g) means, operative when said preceding vehicle is in said second region, for periodically calculating a distance between said preceding vehicle and said controlled vehicle based on a measured travel time between the generation of said transmitted waves and the receipt, in said receiving means, of said reflected waves, said distance defined by l2i for the most recent calculation at time ti and l2i-1 for the immediately preceding calculation at time ti-1,(h) means for storing the distances l1i-1 and l2i-1,(i) means operative after said preceding vehicle is in said first region during time ti-1 for determining if |l1i -|l1i-1 |<
α
, where α
is a predetermined constant and, if the unequality is true, for identifying said preceding vehicle as a target vehicle and as being in said first region at time ti and for generating said control signal based on l1i and said determined controlled vehicle speed, and(j) means, operative if |l1i -l1i-1 |≧
α
for determining if |l2i -l1i-1 |<
α and
if |l2i -l1i-1 |<
α
identifying said preceding vehicle as being in said second region at time ti and as said target vehicle and for generating said control signal based on l2i and said determined controlled vehicle speed.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and system for detecting a presence of a preceding vehicle moving in a front detection area of a controlled vehicle. In the method and system thereof, a plurality of laser or other kinds of beams are transmitted to any object present in the front detection area and the plurality of reflected beams are received so that the respective distances to the reflecting objects are measured on the basis of the propagation delay times between the transmission and reception of the beams. In the method and system thereof, each absolute difference between the current value of distance measured by any one of the beams and any one of previous value of distance measured by the corresponding or another one of the beams before a predetermined time (corresponds to an interruption time of a processing routine) is calculated and compared to a predetermined distance value which is relatively small in order to determine that the preceding vehicle which has been detected by any one of the beams within the predetermined time is the same as that which is currently detected by any one of the beams. Therefore, the presence of the preceding vehicle can accurately be detected without mistaking the preceding vehicle for another vehicle moving on a different traffic lane or as a stationary object located at either side of a traffic lane. This is true even when the controlled vehicle and preceding vehicle move on a curve road. Vehicle speed can be controlled to track the real preceding vehicle.
-
Citations
16 Claims
-
1. Apparatus for controlling the speed of a controlled vehicle to maintain a predetermined distance to a preceding vehicle identified as a target vehicle comprising:
-
(a) means for determining the speed of said controlled vehicle, (b) a control vehicle speed adjustment mechanism responsive to a control signal for controlling the speed of said controlled vehicle, (c) transmitter means for generating transmitted waves toward a predetermined region preceding said controlled vehicle, (d) means for receiving waves reflected from objects in said predetermined region, (e) said predetermined region divided into at least a first and second adjacent regions and at least one of (1) said transmitter means transmitting separately defined transmitting waves into each of said first and second adjacent regions and (2) said receiver means having at least first and second aperture characteristics so as to distinguish waves reflected from each of said first and second adjacent regions, (f) means, operative when said preceding vehicle is in said first region, for periodically calculating a distance between said preceding vehicle and said controlled vehicle based on a measured travel time between the generation of said transmitted waves and the receipt, in said receiving means, of said reflected waves, said distance defined by l1i for the most recent calculation at time ti and l1i-1 for the immediately preceding calculation at time ti-1, (g) means, operative when said preceding vehicle is in said second region, for periodically calculating a distance between said preceding vehicle and said controlled vehicle based on a measured travel time between the generation of said transmitted waves and the receipt, in said receiving means, of said reflected waves, said distance defined by l2i for the most recent calculation at time ti and l2i-1 for the immediately preceding calculation at time ti-1, (h) means for storing the distances l1i-1 and l2i-1, (i) means operative after said preceding vehicle is in said first region during time ti-1 for determining if |l1i -|l1i-1 |<
α
, where α
is a predetermined constant and, if the unequality is true, for identifying said preceding vehicle as a target vehicle and as being in said first region at time ti and for generating said control signal based on l1i and said determined controlled vehicle speed, and(j) means, operative if |l1i -l1i-1 |≧
α
for determining if |l2i -l1i-1 |<
α and
if |l2i -l1i-1 |<
α
identifying said preceding vehicle as being in said second region at time ti and as said target vehicle and for generating said control signal based on l2i and said determined controlled vehicle speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for controlling the speed of a controlled vehicle to maintain a predetermined distance to a preceding vehicle identified as a target vehicle comprising the steps of:
-
(a) determining the speed of said controlled vehicle, (b) controlling the speed of said controlled vehicle in response to a control signal, (c) generating transmitted waves toward a predetermined region preceding said controlled vehicle, (d) receiving waves reflected from objects in said predetermined region, (e) dividing said predetermined region into at least a first and second adjacent regions and at least one of (1) transmitting separately defined transmitting waves into each of said first and second adjacent regions and (2) distinguishing the received reflected waves in a receiver as emanating from said first or second adjacent regions on the basis of aperture characteristics of said receiver, (f) when said preceding vehicle is in said first region, periodically calculating a distance between said preceding vehicle and said controlled vehicle based on a measured travel time between the generation of said transmitted waves and the receipt, in said receiver, of said reflected waves, said distance defined by l1i for the most recent calculation at time ti and l1i-1 for the immediately preceding calculation at time ti-1, (g) when said preceding vehicle is in said second region, periodically calculating a distance between said preceding vehicle and said controlled vehicle based on a measured travel time between the generation of said transmitted waves and the receipt, in said receiver, of said reflected waves, said distance defined by l2i for the most recent calculation at time ti and l2i-1 for the immediately preceding calculation at time ti-1, (h) storing said distances l1i-1 and l2i-1, (i) after said preceding vehicle is in said first region during time ti-1 determing if |l1i -l1i-1 |<
α
where α
is a predetermined constant and, if the unequality if true, identifying said preceding vehicle as a target vehicle and as being in said first region at time ti and generating said control signal based on l1i and said determined controlled vehicle speed,(j) if |l1i -l1i-1 |≧
α
, determining if |l2i -l1i-1 |<
α and
if |l2i -l1i-1 |<
α
identifying said preceding vehicle as being in said second region at time ti and as said target vehicle and generating said control signal based on l2i and said controlled vehicle speed. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
Specification