Event sensor

Abstract

An automatic timing measurement system that provides a measure of time of passage of a watercraft through a prescribed course. Algorithms based on inertial or other estimates augmented by GPS speed/position measurements are used to track position of a watercraft. Said position estimates are used to allow the locations of prescribed courses to be mapped and memorized. Algorithms are then used to allow the apparatus to automatically detect passage of a watercraft through mapped courses for the purpose of measuring and reporting time of passage of said watercraft past key points in said course, and for modifying the behavior of the speed control portion of the apparatus if necessary at certain points in the mapped course. A measure of accuracy of driver steering can be provided along with the ability to automatically steer the watercraft through the course if “steer-by-wire” mechanism is available. GPS speed control is augmented with a secondary velocity measurement device that measures speed over water resulting in an optional user selectable real-time compensation for water current. Furthermore, GPS is used as the key input to produce boat speed-based pull-up profiles.

1 . A system for detecting the time of an event, said system comprising:
 a position observer subsystem;   a computing device in communication with said position observer system;   non-volatile storage programmed with locational information describing at least one water course;   wherein said computing device is adapted to compute a position of a watercraft relative to said water.   
   
   
       2 . The system of  claim 1  further comprising
 A user interface allowing driver inputs to permanently store and identify locations of a prescribed course using measurements derived by  1  above.   
   
   
       3 . The system of  claim 2  wherein said user interface further comprises a progress indicator adapted to substantially represent said watercrafts position relative to said mapped water course. 
   
   
       4 . The system of  claim 2  wherein said user interface is further adapted to provide an audible signal when said watercraft crosses the plane of a buoy. 
   
   
       5 . The system of  claim 1  wherein said computing device is adapted to automatically detect passage of said watercraft through defined points in said course. 
   
   
       6 . The system of  claim 1  wherein
 said permanent storage medium contains a plurality of mapped water courses; and   wherein said computing device is adapted to automatically detect which of said plurality of mapped water courses said watercraft is entering.   
   
   
       7 . The system of  claim 1  wherein said computing device is adapted to measure driver accuracy in steering said watercraft through said mapped water course. 
   
   
       8 . The system of  claim 1   wherein said computing device is adapted to automatically compute a desired path through a mapped course; and   further comprising a control system adapted to steer said watercraft along an actual path substantially in conformance with said desired path.   
   
   
       9 . The system of  claim 1  further comprising
 A computing device adapted to map and display the track of a skier relative to the course location in real time.   
   
   
       10 . The system of  claim 1  further comprising
 An algorithm adapted to map and log the track of a skier relative to the course location based on post-processing data.   
   
   
       11 . An apparatus for measuring the position of a watercraft, said apparatus comprising:
 a GPS device capable of computing a substantially correct position of said water craft;   a permanent storage medium containing locational information for at least one memorized water course;   wherein said GPS device is adapted to calculate a position of said watercraft relative to said at least one memorized water course.   
   
   
       12 . A method of detecting an event comprising the steps of:
 recording map data into a memory;   receiving a velocity signal and a location signal;   outputting a normalized signal based upon said velocity signal and said location signal;   comparing said normalized to said map data;   outputting said even based upon said comparison.