Method and apparatus for 3-D accelerometer based slope determination, real-time vehicle mass determination, and vehicle efficiency analysis
Three dimensional accelerometer data is used to determine a slope the vehicle is traveling over at a specific point in time. The slope data can then be combined with other metrics to provide an accurate, slope corrected vehicle mass. The vehicle mass can then be used along with other vehicle data to determine an amount of work performed by a vehicle, enabling s detailed efficiency analysis of the vehicle to be performed. To calculate slope, horizontal ground speed (V HGS ) can be calculated using the Pythagorean Theorem. One can take the Z/Up magnitude and divide it by the horizontal ground speed. Replacing Z, x and y with directional vectors enables one to calculate slope. The slope data is then used to determine the mass of the vehicle at that time. Pervious techniques to calculate mass did not factor in slope, and thus are not accurate.
1. A method of using vehicle position data to determine a slope the vehicle is traveling over, the method comprising the steps of:
(a) automatically collecting time indexed three dimensional vehicle position data during the operation of a vehicle;
(b) using a computing device to determine a horizontal ground speed of the vehicle at a specific point in time based on the vehicle position data at that point in time; and
(c) using a computing device to determine the slope the vehicle is traveling over at that point in time, based on the horizontal ground speed and Z axis position data at that point in time.
2. The method of claim 1 , wherein the computing device is remote from the vehicle, and further comprising the steps of:
(a) combining the time indexed three dimensional vehicle position data with the slope, to generate slope encoded position data, and
(b) using a wireless data link to convey the slope corrected position data to the computing device.
3. The method of claim 1 , wherein the computing device is integrated into a vehicle telematics unit configured to generate the three dimensional vehicle position data during the operation of a vehicle.
4. A system for using accelerometer data from a vehicle to determine a slope the vehicle is traveling over, comprising:
(a) at least one vehicle data generating component, the at least one vehicle data generating component being configured to generate 3-D accelerometer data during operation of the vehicle data; and
(b) at least one processor, the at least one processor being configured to implement the functions of:
(i) determining a horizontal ground speed of the vehicle at a specific point in time based on the 3-D accelerometer data; and
(ii) determining the slope the vehicle is traveling over at a specific point in time, based on the horizontal ground speed and Z axis 3-D accelerometer data at that point in time.
5. The system of claim 4 , wherein the at least one processor used to determine slope is part of the vehicle.
6. A geographical position system for use in a vehicle, the geographical position system comprising:
(a) a component for collecting 3-D accelerometer data during operation of the vehicle, the 3-D accelerometer data being time indexed;
(b) at least one data port for receiving vehicle data from the vehicle during operation of the vehicle, the vehicle data comprising:
(i) vehicle speed data;
(ii) torque data; and
(iii) engine speed data; and
(c) a processor configured to implement the functions of:
(i) determining a slope the vehicle is traveling over at a specific point in time based on the 3-D accelerometer data; and
(ii) determining a mass of the vehicle at a specific point in time, based on the slope the vehicle is traveling over at that point in time, the vehicle speed data at that point in time, the torque data at that point in time, and the engine speed data at that point in time.
7. The system of claim 6 , wherein the processor is further configured to provide a vehicle mass output that is used by at least one vehicle controller to control operation of the vehicle.
8. The system of claim 6 , further comprising a data link for conveying the 3-D accelerometer data and vehicle mass data to a remote computing device.
9. A data collecting system for use in a vehicle, the system comprising:
(a) a component for collecting 3-D accelerometer data from the vehicle during vehicle operation, the 3-D accelerometer data being time indexed;
(b) at least one data port for receiving vehicle data from the vehicle during operation of the vehicle, the vehicle data comprising:
(i) velocity data;
(ii) torque data; and
(iii) engine speed data; and
(c) a processor for combining the vehicle data and the 3-D accelerometer data together to produce slope corrected mass encoded data; and
(d) a data link for conveying the slope corrected mass encoded data to a remote computing device.
10. The system of claim 9 , wherein the data link comprises a wireless data link and the processor is configured to use the data link to convey the slope corrected mass encoded data to a remote computer in real-time.
11. A vehicle telematics device for use in a vehicle, the vehicle telematics device comprising:
(a) a component for collecting 3-D accelerometer data from the vehicle during vehicle operation, the 3-D accelerometer data being time indexed; and
(b) a processor configured to implement the function of determining a slope the vehicle is traveling over at a specific point in time based on the 3-D accelerometer data.
12. The telematics device of claim 11 , wherein:
(a) the telematics device further comprises at least one data port for receiving vehicle data from the vehicle during operation of the vehicle, the vehicle data comprising:
(i) speed data;
(ii) torque data; and
(iii) engine speed data; and
(b) the processor is further configured to implement the function of determining a mass of the vehicle at a specific point in time, based on the slope the vehicle is traveling over at that point in time, the speed data at that point in time, the torque data at that point in time, and the engine speed data at that point in time.
13. The system of claim 12 , wherein the processor is further configured to provide a vehicle mass output that is used by at least one vehicle controller to control operation of the vehicle.
14. The system of claim 12 , further comprising a data link for conveying the 3-D accelerometer data and vehicle mass data to a remote computing device.
15. The system of claim 12 , wherein the processor is further configured to implement the function of combining the vehicle data and the 3-D accelerometer data together to produce slope corrected mass encoded data; and further comprising a wireless data link for conveying the slope corrected mass encoded data to a remote computing device.