1. A method of limiting the field of view of a microwave motion detector comprising a transmitting antenna and two receiving antennas, comprising the steps of:
transmitting a microwave frequency signal with the transmitting antenna,
receiving microwave frequency signals reflected from a target with the two receiving antennas, each receiving antenna providing a received signal in each of two separate channels,
determining a target ratio from a phase difference between each received signal in the separate channels, and
disregarding motion from the target when the target ratio is less than a predetermined amount.
2. The method of claim 1 wherein the step of determining a target ratio comprises the steps of:
summing and mixing, with a portion of the transmitted microwave frequency signal, the two channels of received reflected signals to generate a sum pattern signal;
subtracting and mixing, with a portion of the transmitted microwave frequency signal, the two channels of received reflected signals to generate a difference pattern signal; and
determining the target ratio from the ratio of the sum pattern signal and the difference pattern signal.
3. The method of claim 1 further comprising the step of generating an alarm condition when the target ratio is more than a predetermined amount.
4. The method of claim 1 further comprising the steps of adapting the target angle limit to meet installation requirements.
5. The method of claim 1 further comprising the step of generating a warning signal when the target ratio is less than a predetermined amount and when the target ratio has increased above a previous target ratio.
6. A microwave motion detector comprising:
a transmitting antenna for transmitting microwave signals,
two receiving antennas for receiving from each antenna reflected transmitted microwave signals from a target in two separate channels, and
processing circuitry adapted to:
determine a target ratio from a phase difference between each signal in the separate channels, and
disregard motion from the target when the target ratio is less than a predetermined amount.
7. The microwave motion detector of claim 6 wherein the processing circuitry is adapted to determine the target ratio by:
summing and mixing, with a portion of the transmitted microwave frequency signal, the two channels of received reflected signals to generate a sum pattern signal;
subtracting and mixing, with a portion of the transmitted microwave frequency signal, the two channels of received reflected signals to generate a difference pattern signal; and
determining the target ratio from the ratio of the sum pattern signal and the difference pattern signal.
8. The microwave motion detector of claim 6 wherein the processing circuitry is further adapted to generate an alarm condition when the target ratio is more than a predetermined amount.
9. The microwave motion detector of claim 6 wherein the processing circuitry is further adapted to generate a warning signal when the target ratio is less than a predetermined amount and when the target ratio has increased above a previous target ratio.
10. An alarm system comprising:
a PIR sensor with a PIR detection pattern,
a microwave motion detector with a microwave detection pattern that is wider than and overlaps the PIR detection pattern, wherein the microwave motion detector comprises a transmitting antenna for transmitting microwave signals and two receiving antennas for receiving reflected transmitted microwave signals from a target in two separate channels, and
processing circuitry adapted to:
determine a target ratio from a phase difference between each signal in the separate channels, and
disregard motion from the target when the target ratio is less than a predetermined amount.
11. The alarm system of claim 10 wherein the processing circuitry is adapted to determine the target ratio by:
summing and mixing, with a portion of the transmitted microwave frequency signal, the two channels of received reflected signals to generate a sum pattern signal;
subtracting and mixing, with a portion of the transmitted microwave frequency signal, the two channels of received reflected signals to generate a difference pattern signal; and
determining the target ratio from the ratio of the sum pattern signal and the difference pattern signal.
12. The alarm system of claim 10 wherein the processing circuitry is further adapted to generate an alarm condition when the target ratio is more than a predetermined amount.
13. The alarm system of claim 10 wherein the processing circuitry is further adapted to transmit an alarm signal when the target ratio is more than the predetermined amount and the PIR sensor also detects the target.
14. The alarm system of claim 10 wherein the processing circuitry is further adapted to:
automatically select a target angle limit from a number of stored target angle limits based on a predefined condition occurring, and
select from a memory look up table the predetermined amount that corresponds to the selected target angle limit.
15. The alarm system of claim 10 wherein the processing circuitry is further adapted to generate a warning signal when the target ratio is less than a predetermined amount and when the target ratio has increased above the previous determined target ratio.
16. The alarm system of claim 13 wherein the predetermined amount corresponds to a target angle that is equal to the PIR detection pattern.
17. The alarm system of claim 13 wherein the predetermined amount corresponds to a target angle that is less than the PIR detection pattern.
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 control system for controlling a mechanical system having first and second electrical machines, the control system comprising:
a controller component operable to receive a first signal which relates to a measured parameter of a first electrical machine and a second signal which relates to a reference parameter of the first electrical machine, the controller component being operable to use the first signal and the second signal to produce a first control signal;
a first filter component operable to receive the first signal from the first electrical machine and to use the first signal to produce a second control signal;
a second filter component operable to receive a third signal which relates to a reference parameter of a second electrical machine and to use the third signal to produce a third control signal;
a first output component operable to receive the first control signal and the second control signal and to combine the first and second control signals to produce a first output control signal for provision to the first electrical machine; and
a second output component operable to receive the first control signal and the third control signal and to combine the first and third control signals to produce a second output control signal for provision to the second electrical machine.
2. A control system as claimed in claim 1, wherein the first output control signal for provision to a first converter component operable to drive the first electrical machine.
3. A control system as claimed in claim 1, wherein the second output control signal is for provision to a second converter component operable to drive the second electrical machine.
4. A control system as claimed in claim 1, wherein the first signal is to comprise:
a measured rotational speed of the first electrical machine.
5. A control system as claimed in claim 1, wherein the second signal is to comprise:
a reference rotational speed.
6. A control system as claimed in claim 1, wherein the third signal is to comprise:
a measured rotational speed of the second electrical machine.
7. A control system as claimed in claim 1, wherein the third signal is to comprise:
a reference rotational speed.
8. A control system as claimed in claim 1, wherein the first output control signal is a torque command.
9. A control system as claimed in claim 1, wherein the second output control signal is a torque command.
10. A control system as claimed in claim 1, in combination with first and second electrical machines, each mechanically coupled to a load.
11. A control system as claimed in claim 10, wherein each mechanical coupling is a flexible coupling.
12. A control system as claimed in claim 1, in combination with first and the second electrical machines which each act upon a load, and wherein the first and the second electrical machines are mechanically coupled to one another via the load.
13. A control system as claimed in claim 12, wherein each mechanical coupling is a flexible coupling.
14. A control system as claimed in claim 1, in combination with n electrical machines, said control system comprising:
a (n+1)th filter component operable to receive a (n+1)th signal which relates to a reference parameter of a nth electrical machine from that nth electrical machine and to use the (n+1)th signal to produce a (n+1)th control signal; and
a nth output component operable to receive the first control signal and the (n+1)th control signal and to combine the first and (n+1)th control signals to produce a nth output control signal for provision to the nth electrical machine.
15. A method for controlling a mechanical system having first and second electrical machines, the method comprising:
receiving a first signal relating to a measured parameter of the first electrical machine;
receiving a second signal relating to a first reference parameter of the first electrical machine;
receiving a third signal relating to a measured parameter of a second electrical machine;
producing a first control signal from the first and second signals using a controller component;
producing a second control signal from the first signal using a first filter component;
producing a third control signal from the third signal using a second filter component;
producing a first output control signal from the first and the second control signals using a first output component;
producing a second output control signal from the first and third control signals using a second output component;
supplying the first output control signal to the first electrical machine; and
supplying the second output control signal to the second electrical machine.
16. A method as claimed in claim 15, comprising:
mechanically coupling each of the first and second electrical machines to a load.
17. A method as claimed in claim 15, comprising:
mechanically coupling the first and second electrical machines to one another via a load, and wherein the first and the second electrical machines each act upon the load.
18. A method as claimed in claim 15, for controlling n electrical machines, wherein the method comprises:
supplying a (n+1)th filter component a (n+1)th signal which relates to a reference parameter of a nth electrical machine from that nth electrical machine for producing (n+1)th signal to produce a (n+1)th control signal; and
supplying a nth output component the first control signal and the (n+1)th control signal, for combining the first and (n+1)th control signals to produce a nth output control signal for provision to the nth electrical machine.
19. A method of controlling a mechanical system which includes first and second electric motors that are mechanically coupled to one another, the method comprising:
supplying control signals to the first and second electric motors using speed feedback and a self-tuned adaptive feedforward filter.
20. A method as claimed in claim 19, wherein the feedforward filter provides oscillation damping control for torque commands provided to the first and second electric motors connected via a dual pinion drive system.