1. A computer implemented method for tracking objects using a surveillance database, the surveillance database storing events acquired by a set of sensors and sequences of images acquired by a set of cameras, each event and image having an associated location and time, the method comprising the steps of:
linking sequences of temporally and spatially adjacent events sensed by the set of sensors to form a set of tracklets, each tracklet beginning with a track-start node, a track-join node or a tracklet-split node and ending with a track-end node, the tracklet-join node or the tracklet-split node, the tracklet-join nodes occurring where multiple preceding tracklets merge to a single successor tracklet and the track-split nodes occurring where a single preceding tracklet diverges to multiple successor tracklets;
selecting a subset of sensors;
identifying a subset of tracklets associated with the subset of sensors
selecting a single tracklet from the subset of tracklet as a starting tracklet;
aggregating all tracklets temporally and spatially adjacent to the starting tracklet to construct a tracklet graph; and
disambiguating and eliminating the track-join nodes and the track-split nodes from the tracklet graph to determine a track of an object in the environment.
2. The method of claim 1, in which the disambiguating further comprising:
displaying available images temporally and spatially related to the events of the tracklet graph to identify the object.
3. The method of claim 1, in which the sensors are infra-red motion sensors, and the cameras are movable.
4. The method of claim 1, in which the sensors using wireless transmitters for transmitting the events.
5. The method of claim 1, further comprising:
retrieving the sequences of images only when events are detected by sensors in a view of a particular camera.
6. The method of claim 5, further comprising:
directing the particular camera at a general vicinity of the particular sensor when a particular event is sensed.
7. The method of claim 1, in which the aggregating is performed according to temporal and spatial constraints.
8. The method of claim 8, in which the temporal and spatial constraints are selected by a user.
9. The method of claim 8, in which the temporal and spatial constraints are learned over time.
10. The method of claim 1, further comprising:
drawing the track on a floor plan of the environment.
11. The method of claim 1, further comprising:
associating particular sequences of images with the tracklets.
12. The method of claim 11, further comprising:
collecting the particular sequences of images associated with the track as video evidence related to the track and object.
13. The method of claim 1, further comprising:
identifying sensors with cameras at any given time.
14. The method of claim 1, further comprising:
identifying particular events visible in the sequences of images at any given time.
15. The method of claim 14, further comprising:
reducing the video evidence to only images corresponding to visible sensor activations.
16. The method of claim 1, in which the linking step is performed periodically and the set of tracklets are pre-stored in the surveillance database.
17. A system for tracking objects using a surveillance database, the surveillance database storing events acquired by a set of sensors and sequences of images acquired by a set of cameras, each event and image having an associated location and time, the system comprising:
means for linking sequences of temporally and spatially adjacent events sensed by the set of sensors to form a set of tracklets, each tracklet beginning with a track-start node, a track-join node or a tracklet-split node and ending with a track-end node, the tracklet-join node or the tracklet-split node, the tracklet-join nodes occurring where multiple preceding tracklets merge to a single successor tracklet and the track-split nodes occurring where a single preceding tracklet diverges to multiple successor tracklets;
means for selecting a staring tracklet;
a user interface selecting a subset of sensors;
means for aggregating all tracklets temporally and spatially adjacent to the starting tracklet to construct a tracklet graph; and
means for disambiguating and eliminating the track-join nodes and the track-split nodes from the tracklet graph to determine a track of an object in the environment.
18. The system of claim 17, in which the disambiguating further comprises:
means for displaying available images temporally and spatially related to the events of the tracklet graph to identify the object.
19. The system of claim 18, in which the sensors are infra-red motion sensors, and the cameras are movable.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A method for controlling a brake system of a vehicle, comprising the steps of:
modifying a braking force at wheel brakes of the vehicle when the brake system is controlled by a driver of the vehicle;
determining at least one performance quantity indicative of a hazardous situation as a function of a distance from the vehicle to an obstacle located in front of the vehicle;
triggering an automatic braking action using at least one signal when at least one predetermined threshold value is exceeded, the at least one signal representing an operation of a braking element of at least one of the wheel brakes, wherein the at least one predetermined threshold value is dependent on the at least one performance quantity; and
if a potential danger of a hazardous situation increases, increasing a sensitivity of the triggering of the automatic braking action.
2. The method according to claim 1, wherein the at least one performance quantity is indicative of a relative velocity of the vehicle with respect to the obstacle.
3. The method according to claim 2, wherein the relative velocity of the vehicle is determined as a function of a change in the distance from the vehicle to the obstacle and as a function of a road speed of the vehicle.
4. The method according to claim 1, wherein the at least one performance quantity is indicative of status information of a cruise control system, the status information indicating whether the cruise control system is operating in a servo control mode.
5. The method according to claim 1,
wherein the automatic braking action is triggered as a function of a closing status of a brake switch of the vehicle in the hazardous situation, and
wherein the closing status is detected as a function of the at least one performance quantity.
6. The method according to claim 1, further comprising the step of:
modifying the at least one predetermined threshold value only if a cruise control system of the vehicle is inactive.
7. The method according to claim 1, wherein the braking force is modified by increasing or decreasing the braking force.
8. A device for controlling a brake system of a vehicle having wheel brakes, the device comprising:
a control unit modifying a brake force at the wheel brakes when a driver of the vehicle controls a braking input, the control unit receiving a signal representing an operation of a control element for at least one of the wheel brakes activated by the driver, the control unit including an arrangement providing at least one predetermined threshold value for triggering an automatic braking action of the vehicle,
wherein the control unit initiates the automatic braking action when an operating quantity-exceeds the at least one predetermined threshold value, and
wherein the control unit modifies the at least one predetermined threshold value as a function of at least one performance quantity indicative of a hazardous situation, the at least one performance quantity being determined as a function of a distance from the vehicle to an obstacle located in front of the vehicle.
9. The device according to claim 8, wherein the control unit modifies a brake force by increasing or decreasing the brake force.
10. The device according to claim 8, further comprising:
a further control unit controlling an adaptive cruise control system and providing the at least one performance quantity to the control unit.