Method and system for determining that a user has operated a vehicle ignition switch
View Patent ↗In telematics device mounted to a vehicle, an auxiliary processor detects an interrupt from an accelerometer and forwards the interrupt to a main processor—the interrupt wakes up the processor from a sleep mode. The main processor may then compare vehicle voltage and/or a value for a speed parameter to predetermined criteria to determine whether the interrupt was a false positive or if the accelerometer missed a detection of a user cranking up the vehicle. The main processor may also enter a conditional state if monitored information meets a minimum threshold. During the conditional state, the processor may operate according to rules for a current operational state and also according to rules for a changed state. The threshold for deeming a changed operational state is higher than for entering a conditional state to evaluate whether a change of operational state (i.e., on to off, or off to on) occurred.
1. A method for determining that a user has operated a vehicle's ignition initiating device, comprising:
monitoring acceleration of the vehicle with an accelerometer;
generating with the accelerometer a wakeup command signal if acceleration of the vehicle exceeds a predetermined accelerometer trigger threshold value;
monitoring with a processor a diagnostic port output for signals containing diagnostic records;
evaluating with the processor diagnostic records from the diagnostic port;
setting a wakeup status indicator to indicate a valid wakeup command signal if operating information contained in the diagnostic records satisfies predetermined criteria, wherein the operating information includes a value for a speed parameter; and
if the speed value in a first diagnostic record after generation of the wakeup command exceeds a predetermined speed value:
decreasing the value of the predetermined accelerometer trigger threshold value; and
setting the wakeup status indicator to indicate a valid wakeup command signal.
2. The method of claim 1 wherein the speed parameter is engine speed.
3. The method of claim 1 wherein the speed parameter is vehicle speed.
4. The method of claim 1 wherein the predetermined accelerometer trigger threshold value is 128 thousandths of the acceleration due to gravity.
5. The method of claim 1 wherein the step of setting a wakeup status indicator includes indicating a valid wakeup signal if operating information contained in the diagnostic records satisfying predetermined criteria occurs and if evaluation of the diagnostic records indicate that a computer system of the vehicle is responding to requests for diagnostic records.
6. A method for determining that a user has operated a vehicle's ignition initiating device, comprising:
monitoring acceleration of the vehicle with an accelerometer;
generating with the accelerometer a wakeup command signal if acceleration of the vehicle exceeds a predetermined accelerometer trigger threshold value;
monitoring with a processor a diagnostic port output for signals containing diagnostic records;
evaluating with the processor diagnostic records front the diagnostic port;
setting a wakeup status indicator to indicate a valid wakeup command signal if operating information contained in the diagnostic records satisfies predetermined criteria, wherein the operating information includes a value for a speed parameter; and
if evaluation of the diagnostic records for a first predetermined period indicates that a computer system of the vehicle is not responding to requests for diagnostic records or that the speed parameter value is substantially zero, setting the wakeup status indicator to indicate a false positive wakeup command signal;
incrementing a false positive counter value;
comparing the false positive counter value to a predetermined false positive occurrence value during a second predetermined period; and
increasing the value of the predetermined accelerometer trigger threshold value if the false positive counter equals the predetermined false positive occurrence value during the second predetermined period.
7. The method of claim 6 wherein the first predetermined period is five minutes, the second predetermined period is twenty four hours, and the predetermined false positive occurrence value is five.
8. A telematics device configured to perform a method for determining that a user has operated a vehicle's ignition initiating device, comprising:
a processor an accelerometer configured to perform the steps of:
monitoring acceleration of the vehicle with an accelerometer device coupled to the vehicle;
generating a wakeup command signal if the acceleration of the vehicle exceeds a predetermined accelerometer trigger threshold value; and a processor configured to perform the steps of:
monitoring a diagnostic port output for signals containing diagnostic records;
evaluating diagnostic records from the diagnostic port; and
setting a wakeup status indicator to indicate a valid wakeup command signal if operating information contained in the diagnostic records satisfies predetermined criteria, wherein the operating information includes a value for a speed parameter;
if evaluation of the diagnostic records for a first predetermined period indicates that a computer system of the vehicle is not responding to requests for diagnostic records or that the speed parameter value is substantially zero,
setting the wakeup status indicator to indicate a false positive wakeup command signal;
incrementing a false positive counter value;
comparing the false positive counter value to a predetermined false positive occurrence value during a second predetermined period; and
increasing the value of the predetermined accelerometer trigger threshold value if the false positive counter equals the predetermined false positive occurrence value during the second predetermined period.
9. The telematics device of claim 8 wherein the speed parameter is engine speed.
10. The telematics device of claim 8 wherein the speed parameter is vehicle speed.