What is claimed is:
1. A motor control apparatus comprising a stop position prediction controller for instructing deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a predetermined position, said predetermined period of time corresponding to a predetermined condition upon arrival of said subject to be driven at said predetermined position, and said predetermined position being at a predetermined distance before a target stop position of the subject to be driven.
2. The motor control apparatus according to claim 1 wherein said predetermined period of time is determined to a value that ensures said subject to be driven stops at said target stop position.
3. The motor control apparatus according to claim 1 wherein said motor is a paper feeding motor of a printer.
4. A motor control apparatus comprising a stop position prediction controller for instructing deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a speed measuring position, said predetermined period of time corresponding to a current speed of said motor upon arrival of said subject to be driven at said speed measuring position, and said speed measuring position being at a predetermined distance before a target stop position of the subject to be driven.
5. The motor control apparatus according to claim 4 wherein said predetermined period of time is determined to be in an extent that ensures deenergization of said motor is instructed before arrival of said subject to be driven at said target stop position.
6. The motor control apparatus according to claim 4 wherein said predetermined period of time varies substantially in reverse proportion to said current speed of the motor upon arrival of said subject to be driven at said speed measuring position.
7. The motor control apparatus according to claim 4 wherein said predetermined period of time is determined to a value that ensures said subject to be driven stops at said target stop position.
8. The motor control apparatus according to claim 4 wherein said motor is a paper feeding motor of a printer.
9. A motor control apparatus comprising:
a position calculator for calculating and outputting a current position of a subject to be driven by a motor on the basis of encoder pulses output from an encoder in response to rotation of the motor;
a speed calculator for calculating and outputting a current speed of said motor on the basis of said encoder pulses; and
a stop position prediction controller for outputting a deenergization instruction signal, which instructs deenergization of said motor, a predetermined period of time later than arrival of said subject to be driven at a speed measuring position, said predetermined period of time corresponding to said current speed of said motor upon arrival of said subject to be driven at said speed measuring position, and said speed measuring position being at a predetermined distance before a target stop position of said subject to be driven.
10. The motor control apparatus according to claim 9 wherein said predetermined period of time is determined to be in an extent that ensures said deenergization instruction signal is output before arrival of said subject to be driven at said target stop position.
11. The motor control apparatus according to claim 9 further comprising a data storage portion for storing data on relations between the current speed of said motor upon arrival of said subject to be driven at said speed measuring position and said predetermined period of time.
12. The motor control apparatus according to claim 9 wherein said stop position prediction controller measures said predetermined period of time by counting the number of said encoder pulses.
13. The motor control apparatus according to claim 9 wherein said stop position prediction controller measures said predetermined period of time by counting the number of pulses of a predetermined clock.
14. The motor control apparatus according to claim 9 wherein destination of said deenergization instruction signal is a drive signal generator that generates a drive signal for rotatably driving said motor.
15. The motor control apparatus according to claim 9 wherein said predetermined period of time varies substantially in reverse proportion to said current speed of the motor upon arrival of said subject to be driven at said speed measuring position.
16. The motor control apparatus according to claim 9 wherein said predetermined period of time is determined to a value that ensures said subject to be driven stops at said target stop position.
17. The motor control apparatus according to claim 9 wherein said motor is a paper feeding motor of a printer.
18. A motor control method configured to instruct deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a predetermined position, said predetermined period of time corresponding to a predetermined condition upon arrival of said subject to be driven at said predetermined position, and said predetermined position being at a predetermined distance before a target stop position of the subject to be driven.
19. The motor control method according to claim 18 wherein said motor is a paper feeding motor of a printer.
20. A motor control method configured to instruct deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a speed measuring position, said predetermined period of time corresponding to a current speed of said motor upon arrival of said subject to be driven at said speed measuring position, and said speed measuring position being at a predetermined distance before a target stop position of the subject to be driven.
21. The motor control method according to claim 20 wherein, for the purpose of determining said predetermined period of time, data is previously collected and stored concerning relations between the current speed of said motor upon arrival of said subject to be driven at said speed measuring position and said predetermined period of time.
22. The motor control method according to claim 20 wherein said motor is a paper feeding motor of a printer.
23. A motor control method comprising:
a first process for measuring a current position of a subject to be driven by a motor and monitoring whether said subject to be driven has reached a speed measuring position at a predetermined distance before a target stop position of said subject to be driven;
a second process for measuring said current speed of said motor upon arrival of said subject to be driven at said speed measuring position;
a third process for determining a predetermined period of time corresponding to said current speed of said motor upon arrival of said subject to be driven at said speed measuring position; and
a fourth step for instructing deenergization of said motor said predetermined period of time later than arrival of said subject to be driven at said speed measuring position.
24. The motor control method according to claim 23 wherein, for the purpose of determining said predetermined period of time, data is previously collected and stored concerning relations between the current speed of said motor upon arrival of said subject to be driven at said speed measuring position and said predetermined period of time.
25. The motor control method according to claim 23 wherein said motor is a paper feeding motor of a printer.
26. A recording medium of a computer program having recorded a computer program for executing in a computer system a motor control method configured to instruct deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a predetermined position, said predetermined period of time corresponding to a predetermined condition upon arrival of said subject to be driven at said predetermined position, and said predetermined position being at a predetermined distance before a target stop position of the subject to be driven.
27. A recording medium of a computer program having recorded a computer program for executing in a computer system a motor control method configured to instruct deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a speed measuring position, said predetermined period of time corresponding to a current speed of said motor upon arrival of said subject to be driven at said speed measuring position, and said speed measuring position being at a predetermined distance before a target stop position of the subject to be driven.
28. A recording medium of a computer program having recorded a computer program for executing in a computer system a motor control method, said motor control method comprising:
a first process for measuring a current position of a subject to be driven by a motor and monitoring whether said subject to be driven has reached a speed measuring position at a predetermined distance before a target stop position of said subject to be driven;
a second process for measuring said current speed of said motor upon arrival of said subject to be driven at said speed measuring position;
a third process for determining a predetermined period of time corresponding to said current speed of said motor upon arrival of said subject to be driven at said speed measuring position; and
a fourth step for instructing deenergization of said motor said predetermined period of time later than arrival of said subject to be driven at said speed measuring position.
29. A motor control apparatus having a position detector for detecting the position of paper to be driven by a paper feeding motor on the basis of output pulses of an encoder that rotates in response to rotation of the paper feeding motor, and a drive controller for controllably driving said paper feeding motor by additionally applying a current value to said paper feeding motor on the basis of a target feeding value of said paper and an output of said position detector, characterized in:
generating a current value signal causing said paper to stop or move in the reverse direction from the normal paper feeding direction in response to output pulses given from said encoder after the feeding amount of said paper reaches said target feeding value, and controllably driving said paper feeding motor by said drive controller in response to said current value signal.
30. The motor control apparatus according to claim 29 further comprising:
a pulse counter for counting output pulses of said encoder during movement of said paper in said reverse direction from the normal paper feeding direction after the feeding amount of said paper reaches said target feeding value and for outputting an instruction signal when the count value reaches a predetermined value; and
a current value signal generator for generating said current value signal upon receipt of said instruction signal or during movement of said paper in the reverse direction from the normal paper feeding direction.
31. The motor control apparatus according to claim 30 wherein said current value signal generator includes:
a detector for detecting whether said paper remains still, or is moving in the reverse direction from the normal paper feeding direction, in response to outputs from said encoder; and
a current value determiner for determining and outputting said current value signal in response to said instruction signal or a result of detection by said detector.
32. The motor control apparatus according to claim 31 wherein said current value determiner outputs the same current value signal as the latest current value signal when said paper remains still, and generates a current value signal that is smaller in absolute value than the latest current value signal but equal in sign when said paper is moving in the reverse direction from the normal paper feeding direction.
33. A motor control method comprising the steps of:
generating a current value signal causing paper to stop or move in the reverse direction from a normal paper feeding direction in response to output pulses given from an encoder after the paper feeding amount reaches a target feeding value, said encoder rotating in response to rotation of a paper feeding motor; and
controllably driving said paper-feeding motor in response to said current value signal.
34. The motor control apparatus according to claim 33 wherein the step of generating said current value signal includes the steps of:
counting output pulses of said encoder during movement of said paper in the reverse direction from the normal paper feeding direction; and
generating said current value signal when the count value of said output pulses reaches a predetermined value.
35. A recording medium of a computer program having recorded a computer program for executing in a computer system a motor control method, said motor control method comprising the steps of:
generating a current value signal causing paper to stop or move in the reverse direction from a normal paper feeding direction in response to output pulses given from an encoder after the paper feeding amount reaches a target feeding value, said encoder rotating in response to rotation of a paper feeding motor; and
controllably driving said paper-feeding motor in response to said current value signal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of locating an immobile target fixedly positioned at a location via a mobile base, the method comprising:
transmitting a first wireless signal from the mobile base at a first time;
receiving the first wireless signal at the immobile target fixedly positioned at the location;
transmitting a second wireless signal from the immobile target in response to receiving the first wireless signal;
receiving the second wireless signal at the mobile base at a second time;
determining a time difference between the first time and the second time;
determining an angle of arrival of the second wireless signal; and
locating the immobile target based on the angle of arrival and the time difference.
2. The method of claim I, wherein transmitting the first wireless signal comprises:
generating an identification request; and
modulating the identification request with a multiple access scheme.
3. The method of claim 2, wherein the multiple access scheme comprises at least one of a code-division multiple access (\u201cCDMA\u201d) scheme, a direct sequence CD MA (\u201cDS-CDMA\u201d), a synchronous CDMA (\u201cSCOMA\u201d), and an ultra-wide band multiple access (\u201cUWB-MA\u201d).
4. The method of claim 1, wherein transmitting the first wireless signal comprises providing a carrier frequency between about 2 GHz and about 3 GHz.
5. The method of claim 1, wherein receiving the second wireless signal comprises receiving the second wireless signal at least one of an antenna array and a rake receiver array.
6. The method of claim 1, wherein transmitting the first wireless signal comprises transmitting the first wireless signal using at least one of a long term fading technique, and short term fading technique.
7. The method of claim 1, further comprising providing a communication bandwidth between about 10 MHz and about 10 GHz.
8. The method of claim 1, further comprising beamforming the second wireless signal.
9. The method of claim 1, wherein transmitting the first wireless signal comprises omni-directionally transmitting the first wireless signal.
10. The method of claim 1, wherein determining a time difference comprises determining a velocity of the mobile base.
11. A method of locating an immobile target fixedly positioned at a location from a mobile base, wherein the mobile base has an omni-directional means for transmitting a base wireless signal, and an antenna array means for receiving a target signal and capable of determining a reception angle of the target signal, and the target at the fixed location has a transponding means capable of receiving an activating signal and responding with a target signal, the method comprising:
omni-directionally transmitting the activating signal from the omni-directional means at a first time while moving the mobile base;
activating the transponding means at the immobile target fixedly positioned at the location in response to receiving the activating signal;
transmitting a wireless target signal from the transponding means after the transponding means has been activated;
receiving the target signal at the antenna array means at a second time;
determining from the antenna array means the reception angle of the target signal;
comparing the first time with the second time to obtain a signal travel time; and
locating the immobile target based on the signal travel time and the reception angle of the target signal.
12. The method of claim 11, wherein transmitting the activating signal comprises:
generating an identification request; and
modulating the identification request with a multiple access scheme.
13. The method of claim 12, wherein the multiple access scheme comprises at least one of a code-division multiple access (\u201cCDMA\u201d) scheme, a direct sequence CDMA (\u201cDS-CDMA\u201d), a synchronous CDMA (\u201cCDMA\u201d), and an ultra-wide band multiple access (\u201cUWB-MA\u201d).
14. The method of claim 13, wherein transmitting the activating signal comprises providing a carrier frequency between about 2 and about 3 GHz.
15. The method of claim 11, wherein receiving the target wireless signal comprises receiving the target wireless signal at a rake receiver array.
16. The method of claim 11, wherein transmitting the activating signal comprises transmitting the activating signal using at least one of a long term fading technique, and short term fading technique.
17. The method of claim 11, further comprising providing a communication bandwidth between about 10 MHz and 10 GHz.
18. The method of claim 11, further comprising beamforming the target wireless signal.
19. A method of locating a selected one of a plurality of immobile targets fixedly positioned at respective locations from a mobile base, the method comprising:
transmitting a wireless activating signal from the mobile base at a first time;
activating with the wireless activating signal a transponder on each of the plurality of immobile targets at their respective fixed locations;
in response to activating each transponder, transmitting with each transponder at its fixed location a wireless signal having a unique mobile signature;
receiving the wireless signals at the mobile base at a plurality of arrival times;
comparing the unique mobile signature of each wireless signal with a known unique mobile signature of the selected immobile target;
identifying the wireless signal of the selected immobile target based upon a match between the known unique mobile signal and the unique mobile signal of one of the wireless signals;
determining a reception angle of the wireless signal of the selected immobile target;
comparing the first time with the arrival time of the wireless signal of the selected immobile target to obtain a time difference; and
locating the selected immobile target based on the time difference and the reception angle.
20. The method of claim 19, wherein transmitting the wireless activating signal comprises:
generating an identification request; and
modulating the identification request with a multiple access scheme.
21. The method of claim 20, wherein the multiple access scheme comprises at least one of a code-division multiple access (\u201cCDMA\u201d) scheme, a direct sequence CDMA (\u201cDS-CDMA\u201d), a synchronous CDMA (\u201cSCDMA\u201d), and an ultra-wide band multiple access (\u201cUWB-MA\u201d).
22. The method of claim 19, wherein transmitting the wireless activating signal comprises providing a carrier frequency between about 2 GHz and about 3 GHz.
23. The method of claim 19, wherein receiving the mobile wireless signal comprises receiving the mobile wireless signal at a rake receiver array.
24. The method of claim 19, wherein transmitting the wireless activating signal comprises transmitting the wireless activating signal using at least one of a long term fading technique, and short term fading technique.
25. The method of claim 19, further comprising providing a communication bandwidth between about 10 MHz and 10 GHz.
26. The method of claim 19, further comprising beamforming the mobile wireless signal.