摘要:
In one method for controlling an electric motor, current turn-on and turn-off rotor-position angles for each motor phase are chosen to substantially maximize the absolute value of average motor torque when the motor is operating in two different quadrants of motor torque and motor speed. The first quadrant has positive motor torque and positive motor speed. The second quadrant has negative torque and positive speed. The third quadrant has negative torque and negative speed. The fourth quadrant has positive torque and negative speed. In another method, the motor is operated in at least one of the first and third quadrants and in at least one of the second and fourth quadrants, wherein the absolute value of motor speed is limited when the motor is operating in the first or third quadrants but not in the second or fourth quadrants. In one example, the motor operates a vehicle brake caliper.
摘要:
A magnetic sensor provides an output voltage range having first and second linear slopes. Proper selection of magnetic sensor dimensions enables changes in magnetic flux density upon the passage of at least one tooth and one slot of a target wheel past the magnetic sensor to be represented as a linear magnetic sensor output comprised of at least one linear range whereby linear interpolation of position is possible with appropriate signal processing algorithms.
摘要:
A magnetic position sensor for measuring a position of a ferromagnetic target over a range. The sensor comprises a magnet at least as long as the range and a sensor array mounted upon a surface of the magnet. The array is at least as long as the range and includes a plurality of sensing elements mounted a fixed distance from the surface of the magnet. The magnet length and the fixed distance have values such that a set of relatively constant values, preferably values of magnetic flux density, is measurable in the sensor array in the absence of the ferromagnetic target. A method of making a position sensor is also disclosed, as is a method of measuring the position of a ferromagnetic target over a range.
摘要:
Certain circuit faults in a phase of a multi-pole, switched reluctance, rotary electrical machine are detected; and the machine is selectively operated with a detected circuit fault when the nature of the fault permits continued operation of the phase and the operation of the phase is desirable. The fault may be one of certain short or open circuits in which at least one of the two current controlling electronic switches is operable to control phase current within predetermined limits. In the continued operation when a fault is detected, (1) the phase current is switched off earlier than it would be in the absence of the fault and/or (2) the maximum phase current is reduced compared with that permitted in the absence of the fault; and either or both of these modifications may be a function of motor speed. If the circuit fault adversely affects current control by an electronic switch normally controlling current level, another electronic switch is substituted for current control.
摘要:
A target wheel sensor assembly includes a target wheel, a magnet, and two or more sensing elements placed therebetween. The magnet and the sensing elements are configured so that as the target wheel rotates each of the sensing elements outputs a respective asymmetric signal relative to the direction of rotation of the target wheel or an object mechanically connected to the wheel. Each of these asymmetric signals is differentially combined with one another to determine the direction of motion of the target wheel, and, if optionally desired, the position of the target wheel.
摘要:
A magnetic sensor has magnetically sensitive element located at a side surface, instead of the bottom surface, of a bias magnet, the magnet being located adjacent a magnetic target wheel, wherein the bias magnet is magnetized parallel to the direction of motion of the teeth/slots of the target wheel. The output may be of a single or double frequency. Sampling of output slope can provide information regarding direction of movement of the target wheel. In a second embodiment the bias magnet is magnetized perpendicular to the movement.
摘要:
A sensor assembly for sensing angular position of an object is provided. The assembly may comprise at least one magneto-sensing magnet having a second axis of rotation. The assembly may further comprise a magnet having a second axis of rotation. At least one of the magnet and the magneto-sensing element are rotatable relative to the other. The respective axes of rotation of the magneto-sensing element and the magnet are non-coincident with respect to one another. The magnet is magnetized along one of the following directions: an axial direction and a radial direction.
摘要:
An analog angle encoder includes a non-magnetic stator which is cup-shaped, having a central post carrying at least one magnetosensitive device, and further including a rotor in the form of a ring captured by the stator, the rotor carrying at least one permanent magnet, wherein the rotor is rotatable relative to the stator. As the rotor rotates relative to the stator, the angle of the incident magnetic field changes relative to the magnetosensitive device, thereby causing the output from the device to vary sinusoidally with angular position. It is preferred to use magnetic configurations other than simple six sided magnets in order to achieve a more uniform magnetic field at the magnetosensitive device, as for example by utilizing cylindrical magnets, arcuate (concave faced) magnets, flat ferromagnetic layer pole pieces, arcuate (concave faced) ferromagnetic layer pole pieces, and ferromagnetic return paths.
摘要:
The subject invention provides an assembly for measuring movement of and a torque applied to a shaft extending between first and second ends and being hollow, specifically for measuring rotation and twisting of the shaft. A permanent magnet is disposed within the shaft for producing a parallel magnetic field emanating radially from the shaft. A sensor mechanism is positioned adjacent the shaft to detect the magnetic flux produced in response to the shaft being moved. The sensor mechanism includes a magnetostrictive (MR) material disposed annularly about the shaft and extends between first and second edges. A flux collector extends beyond the first and second edges of the magnetostrictive material to direct the magnetic flux through a Hall sensor to detect an axial component of the magnetic flux in response to twisting. A positional ring extends annularly around and spaced from the shaft and a positional sensor is disposed between the positional ring and the shaft for measuring a radial component of the magnetic flux in response to rotating.
摘要:
A fuel rail assembly of an internal combustion engine includes an axially extending non-round fuel conduit and at least one axially extending stiffening feature integral with said conduit. Integration of the stiffening features in the conduit enables reduction or elimination of the objectionable frequency noise radiated by the fuel rail assembly. By aligning the stiffening features axially relative to the conduit, panels having a relatively small surface area are formed and, thus, the noise radiating surface area is significantly reduced. The axial orientation of the added stiffening features allows the length of the stiffening features to be relatively large, which increases the stiffening effects to provide increased resistance to flexing, thus, reducing the noise radiated by the fuel system of the internal combustion engine.