Wireless position sensing in three dimensions
View Patent ↗A position sensing system enabling dynamic adjustment of the sensing by dynamically adjusting amplifier gain or comparator thresholds in response to received signals. The system compares the time a signal takes to travel from a transmitter in a mobile component to a plurality of receivers in a fixed component and, adjusts the amplifier gain or comparator thresholds if the difference in times measured by the receivers is large or at least one receiver does not detect a signal.
1. A fixed component capable of performing position sensing of a wireless mobile component including a transmitter, the fixed component comprising:
a) a plurality of receivers arranged in a predetermined spaced-apart relationship, each receiver configured to receive a signal;
b) a plurality of timers, each timer being associated with a respective one of the plurality of receivers;
c) a signal processor configured to process signals received at each receiver;
d) a timer control configured to stop a given timer of the plurality of timers at a stop time for the given timer in response to a processed signal provided by the signal processor; and
e) a feedback processor configured to determine the maximum difference between stop times among the plurality of timers, determine if the maximum difference is larger than a specified value and cause an adjustment to the signal processor if the difference is larger than the specified value.
2. A fixed component according to claim 1 , wherein the timer control is further arranged to send a timeout signal to the feedback processor when no signal is received within a time period and the feedback processor is configured to adjust the signal processor in response to a timeout signal.
3. A fixed component according to claim 1 , wherein the signal processor includes an amplifier and adjusting the signal processor comprises varying the gain of the amplifier.
4. A fixed component according to claim 3 , wherein the feedback processor is configured to decrease the gain of the amplifier in response to determining that the maximum difference is larger than a specified value.
5. A fixed component according to claim 2 , wherein the signal processor includes an amplifier, adjusting the signal processor comprises varying the gain of the amplifier, and the feedback processor is configured to increase the gain of the amplifier in response to a timeout signal.
6. A fixed component according to claim 5 , wherein the feedback processor is configured to decrease the gain of the amplifier in response to determining that the maximum difference is larger than a specified value.
7. A fixed component according to claim 1 , wherein the signal processor comprises a comparator and adjusting the signal processor comprises varying the threshold of the comparator.
8. A fixed component according to claim 7 , wherein the feedback processor is configured to increase the threshold of the comparator in response to determining that the maximum difference is larger than a specified value.
9. A fixed component according to claim 2 , wherein the signal processor comprises a comparator, adjusting the signal processor comprises varying the threshold of the comparator, and the feedback processor is configured to decrease the threshold of the comparator in response to a timeout signal.
10. A fixed component according to claim 9 , wherein the feedback processor is configured to increase the threshold of the comparator in response to determining that the maximum difference is larger than a specified value.
11. A fixed component according to claim 1 , wherein the feedback processor is further configured to calculate the average of the times recorded by the timers and adjust the signal processor by a large amount when the average of the times is above a predetermined value and by a small amount when the average of the times is below a predetermined value.
12. A fixed component according to claim 1 , wherein the signal processor is varied in incremental steps.
13. A method of sensing the position of a wireless mobile component including a transmitter by a fixed component including a plurality of receivers arranged in a predetermined spaced-apart relationship, the method comprising the steps of:
a) each receiver receiving a signal;
b) processing the signal received at each receiver to produce a processed signal;
c) receiving a processed signal at a control unit and stopping a timer associated with each one of the plurality of receivers, each respective timer being stopped in response to a processed signal provided by the signal processor;
d) determining the maximum difference between each of the times at which each timer was stopped;
e) determining if the maximum difference is larger than a specified value; and
f) adjusting the processing of the signal if the difference is larger than the specified value.
14. A method of position sensing according to claim 13 , further comprising the step of sending a timeout signal if no signal is received by the receivers within a time period and adjusting the processing of the signal in response to a timeout signal.
15. A method of position sensing according to claim 13 , further comprising the step of calculating the average of the times recorded by the timers and adjusting the processing of the signal by a large amount when the average of the times is above a predetermined value and by a small amount when the average of the times is below a predetermined value.
16. A method of position sensing according to claim 13 , wherein the processing of the signal is varied in incremental steps.
17. A computer program embedded on a non-transitory computer-readable medium, the computer program configured to be carried out on a fixed component to cause the fixed component to carry out the steps of:
a) each receiver receiving a signal;
b) processing the signal received at each receiver to produce a processed signal;
c) receiving a processed signal at a control unit and stopping a timer associated with each one of the plurality of receivers, each respective timer being stopped in response to a processed signal provided by the signal processor;
d) determining the maximum difference between each of the times at which each timer was stopped;
e) determine if the maximum difference is larger than a specified value; and
f) adjusting the processing of the signal if the difference is larger than the specified value.
18. The computer program of claim 17 , the steps further comprising sending a timeout signal no signal is received by the receivers within a time period and adjusting the processing of the signal in response to a timeout signal.
19. The computer program of claim 17 , the steps further comprising calculating the average of the times recorded by the timers and adjusting the processing of the signal by a large amount when the average of the times is above a predetermined value and by a small amount when the average of the times is below a predetermined value.
20. The computer program of claim 17 , wherein the processing of the signal is varied in incremental steps.
21. A fixed component capable of performing position sensing of a wireless mobile component including a transmitter, the fixed component comprising:
a) a plurality of receivers arranged in a predetermined spaced-apart relationship, each receiver configured to receive a signal;
b) a plurality of timers, each timer being associated with a respective one of the plurality of receivers;
c) a signal processor configured to process signals received at each receiver;
d) a control unit configured to stop a given timer of the plurality of timers at a stop time for the given timer in response to a processed signal provided by the signal processor and to send a timeout signal to a feedback processor when no signal is received within a time period; and
e) the feedback processor configured to cause an adjustment to the signal processor in response to the timeout signal.
22. A fixed component according to claim 21 , wherein the feedback processor is further configured to determine the maximum difference between each of the times at which each timer was stopped, determine if the maximum difference is larger than a specified value and cause an adjustment to the signal processor if the difference is larger than the specified value.
23. A method of sensing the position of a wireless mobile component including a transmitter by a fixed component including a plurality of receivers arranged in a predetermined spaced-apart relationship, the method comprising the steps of:
a) each receiver receiving a signal;
b) processing the signal received at each receiver to produce a processed signal;
c) receiving a processed signal at a control unit and stopping a timer associated with each one of the plurality of receivers, each respective timer being stopped in response to a processed signal provided by the signal processor;
d) sending a timeout signal to a feedback processor if a timer is not stopped within a predetermined amount of time; and
e) adjusting the signal processing in response to the timeout signal.
24. A computer program embedded on a non-transitory computer-readable medium, the computer program configured to be carried out on a fixed component including a plurality of receivers to cause the fixed component to carry out the steps of:
a) each receiver receiving a signal;
b) processing the signal received at each receiver to produce a processed signal;
c) receiving a processed signal at a control unit and stopping a timer associated with each one of the plurality of receivers, each respective timer being stopped in response to a processed signal provided b the signal processor;
d) sending a timeout signal to a feedback processor if a timer is not stopped within a predetermined amount of time; and
e) adjusting the signal processing in response to the timeout signal.