2935results about "Anti-hunting elements" patented technology

A drilling device prevents recurrence of an overload condition after occurrence of the overload condition, thereby improving operability and safety in the drilling device. A motor for rotating a drill is connected to an AC power source through a motor control unit, a current detector, and a power switch. A magnet is also connected to the AC power source through the power switch and a full-wave rectifier. The motor control unit rotationally drives the motor on the basis of a signal sent from a main control unit according to a state in which a motor start switch is on. The main control unit controls the motor control unit to gradually reduce a supply voltage to the motor when the motor becomes overloaded, to gradually increase the voltage to the normal power supply condition when the overload condition is vanished, and to stop power supply to the motor if the overload condition continues for a predetermined period.

A system for automatic regulation of daylight admitted by a window in the presence of artificial illumination produced by a high-efficiency (e.g., fluorescent-type) electric lamp. A preferred embodiment, adaptive window covering system 10, consists of an illuminance sensor 11, a conventional control apparatus 12, and a conventional shading means 13. System 10 is used in conjunction with a conventional, high-efficiency, electric lamp 14 and a conventional window 18, in a room 19. Sensor 11 produces a signal dependent on power contained in a portion of the daylight spectrum, but substantially insensitive to power contained in the spectrum of artificial illumination produced by lamp 14. In a preferred embodiment, sensor 11 includes a silicon photodiode and optical low-pass filter to provide a spectral response which extends from approximately 800 to 1200 nanometers, which falls outside the spectrum produced by typical fluorescent lamps (e.g, 300 to 750 nanometers). Sensor 11 is oriented to sample the ambient illumination in room 19, which includes both daylight and artificial components. Control apparatus 12 produces an actuating signal dependent on the output of sensor 11. Shading means 13 varies the amount of daylight admitted by window 18 as a function of the actuating signal produced by control apparatus 12. Thus, system 10 varies the amount of daylight admitted by window 18 as a function of the power contained in a portion of the daylight spectrum, but independent of the power contained in the spectrum produced by lamp 14.

The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

The disclosure relates to General Synchronized Vibration devices that provide haptic feedback to a user and improve the performance of existing vibratory devices. Different actuator types may be employed to provide synchronized vibration, including linear rotary actuators, rotating eccentric mass actuators including interleaved rotating mass actuators, and rocking mass actuators. A controller sends signals to one or more driver circuits to provide adjustment of vibration magnitude, frequency, and direction of the actuators. The system may apply forces onto an object, and a sensor measures a feature(s) of the object. This information is provided to a vibration device controller, which can then modify the vibration waveform to improve overall system performance. Fourier synthesis can be used to approximate arbitrarily shaped waveforms by controlling the phase and frequency of vibration actuators. These waveforms can include asymmetry where the peak force in one direction is higher than the peak force in another direction.

A closed-loop control system that remotely controls a device over a distributed communications system includes a device that is connected to the distributed communications system and that generates super-media feedback signals. A computer is connected to the distributed communications system and includes a controller that provides super-media feedback. The computer generates and transmits command signals using the controller to the device and outputs the super-media feedback signals to the controller. The closed-loop control system is event-based to ensure stability and synchronization of the closed-loop system.

A detection system for detecting a dangerous condition for an operator using a power tool of the type which has an exposed blade relative to a work surface and a protection system for minimizing, if not eliminating the possibility of a user being injured by contacting the blade. In one preferred embodiment of the present invention, a proximity detection system is capable of detecting the presence of a user near the blade of a table saw and a protection system that can either retract the blade below the work surface of the table saw or terminate the drive torque to the blade which can result in rapid stopping of the saw blade by a work piece that is being cut.

A control unit controls a vehicle having a body to allow a user to step on, a power generator arranged to generate power that drives the body, and a first sensor and a second sensor. Each sensor preferably outputs a load value representing a load that has been applied to the body. The control unit preferably includes a processor arranged to output a command value associated with a bias of the load based on first and second load values that have been respectively detected by the first and second sensors, and a drive controller arranged to control the power generator in accordance with the command value.

A motor control system for a brushless and sensorless DC motor for driving a compressor, pump or other application, includes a protection and fault detection circuit for detecting a locked rotor and a rotor which has stopped because of lost rotor phase lock. The motor control system also includes an off-the-shelf motor control integrated circuit having an input for disabling power outputs to the motor phase coils. The protection and fault detection circuit uses a back EMF sampling circuit coupled to the motor phase coils and momentarily disables power to the motor phase coils, via the motor control integrated circuit input, to determine if the motor rotor is rotating. The system also monitors supply voltage, supply current, temperature, and motor speed limits to detect faults and protect system components.

An integrated torsional mode damping method for a current source converter, including a rectifier, an inverter, and a DC link inductor coupled between the rectifier and the inverter, includes sensing a signal representative of torque on a shaft coupled to the inverter or rectifier; using the sensed signal for detecting a presence of a torsional vibration on the shaft; and damping the torsional vibration by modulating active power through the respective inverter or rectifier.

A photovoltaic system includes a plurality of photovoltaic modules and a DC motor connected to a three-phase generator driven by a shaft. The three-phase generator is connected to a power mains. The electric power supplied to the DC motor by the plurality of photovoltaic modules is repeatedly measured and adjusted, by changing an external excitation current of the DC motor, to the peak power attainable at the current ambient temperature and the current incident solar radiation intensity. The peak power is preferably determined by incrementally changing the excitation current in predetermined time intervals, until the supplied electric power produces a power level which can be regarded as the peak power.

A motor control system for a brushless and sensorless DC motor for driving a compressor, pump or other application, includes a protection and fault detection circuit for detecting a locked rotor and a rotor which has stopped because of lost rotor phase lock. The motor control system also includes an off-the-shelf motor control integrated circuit having an input for disabling power outputs to the motor phase coils. The protection and fault detection circuit uses a back EMF sampling circuit coupled to the motor phase coils and momentarily disables power to the motor phase coils, via the motor control integrated circuit input, to determine if the motor rotor is rotating. The system also monitors supply voltage, supply current, temperature, and motor speed limits to detect faults and protect system components.

Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

A light guide with input and output faces 2, 3a is polar-symmetric about the first face 2 and has optical properties such that the angle at which a ray is injected into the first face determines the position at which it leaves the second face 3a, or, if operated in the reverse direction, the position at which the ray enters the second face determines the angle at which the ray leaves the second face. The light guide includes a tapered transparent sheet 3, light from the first face entering at the thick end of this sheet, and the second face forming one face of the tapered sheet. An input / output slab 4 adjoins the tapered sheet 3 for fan-out of light from the first face 2 to the tapered sheet, and a transition region 8 is located between flat and tapered sheets. The polar symmetry means that light rays always travel in line with the taper direction, which suppresses banding. Preferably the light guide further includes a prism device 20 for folding the light so that the flat and tapered sheets can be folded over each other. A method of making such a prism is also disclosed.

An improved system for monitoring vibration of an electric machine is disclosed. According to one embodiment, sensors are positioned in a plane orthogonal to the motor shaft and each sensor detects vibration along at least one axis of the motor. The sensors are oriented such that the polarity of each sensor is reversed. The pairs of sensors may be used to isolate specific vibrations within the motor. According to another embodiment, a sensor may be mounted directly to the motor shaft. The sensor on the motor shaft directly detects vibrations along the motor shaft. Optionally, a second sensor may be mounted to a fixed location within the motor housing, and the combination of the sensor on the motor shaft and the sensor at a fixed location may be used to isolate specific vibrations within the motor. A motor controller may adjust operation of the motor to reduce the isolated vibration.

Automated shade systems comprise motorized window coverings, sensors, and controllers that use algorithms to control operation of the automated shade control system. These algorithms may include information such as: 3-D models of a building and surrounding structures, shadow information, reflectance information, lighting and radiation information, ASHRAE clear sky algorithms, log information related to manual overrides, occupant preference information, motion information, real-time sky conditions, solar radiation on a building, a total foot-candle load on a structure, brightness overrides, actual and / or calculated BTU load, time-of-year information, and microclimate analysis.

A lithographic device and an exposure method utilize mask and substrate tables, and a projection system. A mask having a mask pattern is provided on the mask table. A substrate having a radiation-sensitive layer is provided on the substrate table. The mask is irradiated to project an image of at least a portion of the mask pattern onto the radiation-sensitive layer of the substrate using the projection system. Before or during the projecting, at least one of the mask and substrate tables is positioned using a drive unit that includes a stationary part coupled to a reaction frame of the lithographic device. A position of at least one of the mask and substrate tables is measured using a measuring system having a plurality of measurement sensors that have a stationary part and a movable part. The movable part of one of the sensors is coupled to the one of the mask table and the substrate table whose position is measured, and the stationary parts of the sensors are coupled to a support frame mechanically isolated from the reaction frame.

A wireless operating system (10) utilizing a multi-functional wall station (12) for a motorized door / gate operator includes an operator (50) for controlling the movement of a door / gate (54) between various positions. The system has an operator with a receiver (56) and a wall station transmitter (12) for transmitting a signal (42) to the receiver. The signal initiates separate operator functions in addition to opening and closing of the door / gate. A remote transmitter (70) may send a remote signal (74) received by the receiver, wherein the receiver is capable of distinguishing between the wall station signal (42) and the remote signal (74). The wall station includes a transmitter programming button (24), wherein actuation of the transmitter programming button places the wall station transmitter in a learn mode, and wherein subsequent actuation of the remote transmitter positively identifies the remote transmitter for use with the wall station. A light (66) powered by the operator and a light actuation button (18) provided by the wall station transmitter is included in the system. Actuation of the light actuation button (18) functions to switch the light on or off. A pet height button (22), provided by the wall station transmitter, selectively positions the height of the gate / door (54) from its fully closed position to allow ingress and egress of a pet. A delay-close button (20) closes the door / gate after a predetermined period of time. Actuation of a door installation button (28) sequences the door / gate and said operator through various operational parameters to establish a door operating profile. A keyless entry transmitter (80) and a second wall station may also control the operator.

A method and apparatus provide a state observer control system 600 for a motor 106 that uses an extended Kalman filter 330 to predict initial rotor position and afterwards accurately predict rotor position and / or speed under variable types of loading conditions. A control system model 300 is generated that allows variable setting of an initial rotor position to generate estimated rotor position and speed as outputs. The control system model 300 includes an EKF (extended Kalman filter) estimator 330, speed controller 322, a current controller 324, and a variable load component 310. During operation, EKF estimator 330 estimates rotor speed 327 and position 333 based on reference voltages 402, 404 and currents 1325 generated by speed and current controllers 322, 324 and input from frame transformers 326, 328. Additionally, the reference currents and voltages 402, 404, 1325 are frame-transformed to be used as feedback signals 418, 346 in the system 600 and as drive signals to control power to be applied to a motor load 602.

A guideless stage for aligning a wafer in a microlithography system is disclosed, and a reaction frame is disclosed which isolates both external vibrations as well as vibrations caused by reaction forces from an object stage. In the guideless stage an object stage is disclosed for movement in at least two directions and two separate and independently movable followers move and follow the object stage and cooperating linear force actuators are mounted on the object stage and the followers for positioning the object stage in the first and second directions. The reaction frame is mounted on a base structure independent of the base for the object stage so that the object stage is supported in space independent of the reaction frame. At least one follower is disclosed having a pair of arms which are respectively movable in a pair of parallel planes with the center of gravity of the object stage therebetween. The linear positioning forces of the actuator drive means are mounted and controlled so that the vector sum of the moments of force at the center of gravity of the object stage due to the positioning forces of the drive means is substantially equal to zero. The actuator mounting means can include at least two thin flexible members mounted in series with the primary direction of flex of the members being orthogonal to one another.

During rain, including a light source (5) for radiating light such that the light is transmitted through a vehicle window (2), a light receiving element (6) for sensing an optical signal when the light radiated from the light source (5) is reflected from the raindrop fallen on the vehicle window (2) and performing a photoelectric transduction, and a receiver (9) for receiving the photoelectrically transduced signal from the light receiving element (6) and judging the level of rainfall. The light source (5) and the light receiving element (6) are inclined with respect to the surface of the vehicle window (2) such that the light of the light source (5) directly reflected from the vehicle window (2) exits to the outside of the light receiving element (6) and the light reflected from a raindrop (8) on the vehicle window (2) is received by the light receiving element (6) to operate a vehicle wiper.

The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

A drive unit includes an electric motor as a power source, and a simplified coolant circuit for cooling the electric motor. The drive unit further includes, in the drive unit case, a circulation passage L for coolant for cooling the motor M. A circulation passage F for a second coolant is provided separate from the circulation passage L for coolant. A heat exchange portion C within the circulation passage L for the first coolant is provided in the drive unit case for heat exchange with the second coolant in the circulation passage F, and the first coolant for cooling the electric motor is cooled by heat transfer to the second coolant in that heat exchange portion C. Accordingly, the coolant circuit in the drive unit case is simplified.