Other

Socovar Sec

David Bensoussan

Don Tardio

A system and method for controlling a plant having a minimum phase transfer function P(s) and given an input signal u, the plant having an output y and a plant frequency range comprising a transfer function J(s) comprising the product of a high gain filter J(s) having a gain ksufficient that when |&#x3c9;|&#x2266;&#x3c9;and |1+J(&#x3c9;)|&#x3e;1/M for all &#x3c9; wherein &#x3c9;is selected to obtain a desired time response, and a low pass filter J(s) selected such that |1+J(&#x3c9;)|&#x3e;1/M for all &#x3c9; and J(s) is strictly proper, wherein &#x3b5;&#x3c;1 and M&#x3e;1 and &#x3b5; and M are selected to meet a desired sensitivity requirement. An error signal e is calculated comprising the difference between the system input signal u and the plant output signal y, and the error signal modified according to the transfer function C(s)=P(s)J(s)J(s) and inputting the error signal into the plant. The system and method can be extended to unstable invertible plants. A global sensitivity bound M&#x2267;1 could also be achieved for plants including right half planes zeros. The system and method are shown applied to a read-write head positioning actuator of a hard disk drive, but can be applied equally to other systems such as electrical systems, mechanical systems, industrial processes, military applications, flight control, power generation, computer servo systems, phase lock loops and the like.

System and method for feedback control

A controller associated with a dissipative electric load controls the level of average power applied to the load by an electric energy distribution network that supplies the dissipative load with a supply voltage. The controller comprises a detector for detecting a predetermined pulse duration modulation signal embedded in the level of the supply voltage provided by the distribution network, and a device for transmitting electric power originating from the distribution network to the load. The device for transmitting comprises a device for reducing the level of average power transmitted to the load, in response to a detection of said pulse duration modulation signal in the level of supply voltage. A decrease of the line voltage level for a given duration of power distribution voltage is initiated in order to control the average power consumption of the loads.

Average power level controller

An electronic controller comprising two input terminals between which an AC line and an electrical load are connected in series. A processing unit generates a command signal to control the supply of electrical power to the electrical load which closes an electronic switch also connected between the two input terminals for connecting the AC line and the load in series in a closed loop. A power supply voltage of the controller is provided by a second power supply derived from the two input terminals, consequently from the AC line through the load when the switch is open. When the command signal is generated, an electronic circuit opens the switch which is normally closed by this command signal to maintain the power supply voltage of the controller according to an adequate standard of operation. To energize the controller, the opening of the switch is activated in a temporary and repetitive manner for a certain whole number of cycles of the sector. This opening is whether periodic or occurs while the power supply voltage of the controller transits underneath a predetermined threshold value.

Means for refreshing a triac control circuit power supply

An electronic temperature controller having a great stability and an improved sensitivity to temperature. The controller is designed to operate at preset temperatures depending on the occupancy and/or the presence of light in each of the rooms of a household. A microcomputer supplies control signals to a heating device until the ambient temperature in the room reaches the appropriate preset temperature. To do so, use is made of an electronic regulator of the proportional-integral-differential type. The control signals of course control the amount of energy (i.e. heat) given off by the heating device in the room. This electronic controller permits to regulate temperature automatically and thus save heating energy when the rooms of the house are either unoccupied or not lit. This electronic controller may also incorporate an electronic thermometer, an alarm system and/or a fire alarm. It may also control any appliance in a room depending on a change in occupancy and/or lighting in the room.

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Montreal, Canada

David Bensoussan