Abstract: A variable valve timing mechanism for an internal combustion engine comprising at least one rotary valve (1) having at least two ports terminating as openings (2, 3) in its periphery, a cylinder head (7) having a bore in which the rotary valve (1) rotates, and a window (6) in the bore communicating with a combustion chamber (8). The openings (2, 3) successively align with the window (6) by virtue of the rotation. The mechanism also comprises a drive mechanism (13) driving the rotary valve (1). The at least two ports (2, 3) of the rotary valve (1) are an inlet port and an exhaust port. The drive mechanism (13) varies the angular velocity of the rotary valve (1) at least within a portion of at least one engine cycle while maintaining an average angular velocity over the at least one engine cycle that has a fixed relation to the average angular velocity of crankshaft over the at least one cycle.

Abstract: An angle sensor for sensing the absolute angular position of a rotatable body, such as a rotating shaft of an electric power steering system for an automobile, is disclosed.

Abstract: A sensor for determining the position of a moveable surface having patterned regions is disclosed. The sensor includes an ASIC, at least one lens, and at least one EMR source. The ASIC includes at least one array of EMR sensitive detectors and processing means. The EMR source illuminates the surface. The lens focuses the reflected EMR from the surface and generates an image on the array of EMR sensitive detectors corresponding to the pattern on the surface. The ASIC, the one lens, and the one EMR source are all enclosed in a single housing providing accurate optical alignment of these elements and integrated as a single replaceable module. The processing means of the ASIC processes the image to determine the position of the pattern on the surface. The ASIC and the EMR source are both mounted on a PCB and the PCB is mounted in the housing.

Abstract: An electronic circuit for a capacitive flash analog to digital converter for converting the ratio of first and second analog signals into a digital code representation using an array of parallel capacitive comparator branches. Each branch computing one bit of the digital code simultaneously according to its array index. The first analog signal is applied as a voltage difference between first signal nodes comprising a first positive signal node and a first negative signal node. The second analog signal is, applied as a voltage difference between second signal nodes comprising a second positive signal node and a second negative signal node.

Abstract: An electronic circuit for measuring the position of a spatially periodic intensity pattern of incident radiation includes an array of detectors (1); two or more correlator units (2, 3) each having arrays of capacitors (12, 13) connected to a buffer (14); and a phase angle computing unit (4). The pitch of the array of detectors (1) is smaller than the pitch of the incident intensity pattern so that the latter is oversampled, yielding high accuracy. The detector outputs (17) are weighted by respective fixed capacitance values (15, 16) which vary periodically along arrays of capacitors (12, 13), and a weighted sum of outputs for each correlator unit (2, 3) is output at its respective buffer (14). The capacitance values (15, 16) of respective correlator units (2, 3) are mutually offset by a predetermined phase shift. The analog computation using capacitor arrays (12, 13) is fast and energy efficient, and can be implemented as a VLSI circuit.

Abstract: A method of manufacturing patterns on the surfaces of grating elements of a torque transducer having a shaft comprising first and second rigid torque input members connected by a torsional coupling enabling relative angular deflection between the first and second input members, first and second grating elements respectively associated with the first and second input members, the surfaces of the grating elements being adjacent to each other and able to relatively displace as a function of torque in the shaft, the method comprising the steps of: forming an assembly by rotationally and axially fixing the input members and respective grating elements to the torsional coupling; mounting the assembly in a machine comprising a radiation source arranged to irradiate regions of the surfaces of the grating elements while a relative angular displacement between the torque input members with respect to their zero torque alignment condition is maintained; and simultaneously irradiating regions of the surfaces of the grati

Abstract: A torque transducer having a rotating shaft with first and second substantially rigid torque input members connected by a torsionally compliant coupling that enables angular deflection of the first torque input member relative to the second torque input member as a function of the magnitude of the torque in the shaft. First and second grating elements are attached to or integral with first and second torque input members, respectively. The grating elements have surfaces with alternating regions of high and low reflectivity connected by a torsionally compliant coupling. The surfaces are illuminated by a source of electromagnetic radiation (EMR), which generates patterns on one or more arrays of detectors sensitive to the EMR. The disposition of the patterns is a function of torque applied to the shaft, and the output of the one or more arrays can be processed to produce a measure of the torque applied to the shaft.