Abstract: A test specimen holder for holding a test specimen in a material testing machine includes screw operated actuators with removable blocks of material. Preferably, a plurality of blocks of material is provided with a varying degree of compliance. Alignment guides indicating the relative position of jaw plates are also provided.

Abstract: A steering angle sensing system 1, 26 for measuring the angle position of a vehicle steering wheel is disclosed which uses at least one position magnet 7, 8, G1, G2, G3 coupled to the rotary movement of the steering wheel 2′ as a transducer, and a magnetostrictive transducer 4, 35 as a measuring device and a second measuring device 70, 90 for measuring the angular movement of the vehicle wheels. Magnetostrictive transducer 4, 35 includes an elongated, magnetostrictive waveguide 9, 33 extending over a defined arc section, with mode converter 10, 35 for detecting magnetostrictively generated voltage pulses at one end. The waveguide 9, 33 is stationary related to the rotary movement of at least one position magnet 7, 8, G1, G2, G3 so that, when turning the steering wheel 2′, the magnet field of one position magnet 7, 8, G1, G2, G3 is applied to waveguide 9, 33 in different positions dependent of the position of the steering wheel 2′.

Abstract: A loading assembly for applying a load to a test specimen includes a container having a volume of compressible fluid for providing a spring. A cylinder having a bore operably connected to the container. A piston is slidable in the bore and is operably coupleable to the test specimen. A valve fluidly coupled to the bore selectively provides fluid to the bore to displace the piston. A controller controls the valve to cause nonresonant displacement of the piston.

Abstract: A spherical swivel includes a base assembly having a clevis and a ball joined to the clevis. A swivel eye is movably joined to the ball. An elastomeric band positioning device includes an elastomeric band that is secured at opposite ends to the base assembly and is further secured to the swivel eye.

Abstract: A steering angle sensing system 1 for measuring the angle position of a vehicle steering wheel is disclosed which uses at least one position magnet 7, 8 coupled to the rotary movement of the steering wheel as a transducer, and a magnetostrictive transducer 4 as a measuring device. Magnetostrictive transducer 4 includes an elongated, magnetostrictive waveguide 9 extending over a defined arc section, with mode converter 10 for detecting magnetostrictively generated voltage pulses at one end. The waveguide 9 is stationary related to the rotary movement of at least one position magnet; 7, 8, so that, when turning the steering wheel, the magnet field of one position magnet 7, 8 is applied to waveguide 9 in different positions dependent of the position of the steering wheel.

Abstract: A vehicle suspension apparatus according to the invention includes a vehicle suspension strut and a continuous position sensor coupled to the vehicle suspension strut and adapted to provide information indicative of a continuous position of a first portion of the vehicle suspension strut relative to a second portion of the vehicle suspension strut. The continuous position sensor includes a magnet coupled to the first portion of the vehicle suspension strut and a sensing mechanism coupled to the second portion of the vehicle suspension strut and responsive to the magnet to provide an output indicative of the continuous position of the first portion relative to the second portion.

Abstract: A method and apparatus is disclosed for monitoring an angular displacement, such as angle position and the direction of displacement. The method and apparatus includes at least one resonator placed in proximity to a electrodynamic profile and exciting within said resonator an alternating electromagnetic field. The electromagnetic field should be at a frequency at which the electromagnetic field contacts the electrodynamic profile and then variations of the electromagnetic field parameters are measured for the resonator caused by rotating the electrodynamic profile. Excitation of the resonator is by an electromagnetic field in the form of at least one slowed electromagnetic wave having a suitable energy distribution of the electric and magnetic fields for measuring the electromagnetic field parameters.

Abstract: A system and method for identifying characteristics of a physical system applies substantially identical drive ensembles to the physical system and obtains corresponding responses from the physical system. A repeatable bandwidth of the physical system is estimated as a function of the applied drive ensembles and the corresponding obtained responses. Instructions can be provided on a computer readable medium to perform the method.

Abstract: A magnetostrictive linear position sensor produces a signal which is a time period. It is sometimes required to measure this time period and produce an output in another form which accurately represents the time period. The final output may be a voltage, current, frequency, digital or other signal format. A time period is commonly measured using a clock and a counter. The resolution is limited by the frequency of the clock. An upper limit for the clock frequency is usually set based on power consumption or other circuit constraint. A method and apparatus is disclosed for improving the resolution of a time interval using low power and for providing a response after one time period without averaging.

Abstract: A circuit for providing a current through a load includes a first bridge circuit connectable to the load. The first bridge circuit selectively applies a voltage across the load. A second bridge circuit is connected to the first bridge circuit and is connectable to a power supply. The second bridge circuit selectively applies voltage to terminals of the first bridge circuit.

Abstract: A circuit for measuring current flowing through a load driven by a pulse width modulation (PWM) circuit in response to PWM control signals, according to the present invention, includes a transformer having primary and secondary windings, with the primary winding connected to the load. Current cancellation circuitry coupled to the secondary winding is adapted to apply a cancellation current to the secondary winding and to provide an output which is indicative of a level of current through the load. An inverter coupled to the current cancellation circuitry output provides an inverted current cancellation circuitry output. First and second switches selectively couple one of the current cancellation circuitry output and the inverted current cancellation circuitry output to a load current output which provides an output indicative of the level of current through the load during both static and dynamic load current conditions.

Abstract: A transducer assembly adapted for use for measuring forces and moments including a stationary center load axle having an elongated extend extending along an elongated axis between spaced opposed ends. The transducer assembly including first and second load cells interposed in a force path between opposed first and second ends of the load axle measuring applied load in the suspension load path of a two wheel vehicle.

Abstract: A system and method for calculating the speed of a moving member having an output device providing an output periodic signal as a function of displacement of the moving member includes measuring a time duration for a plurality of first periodic occurrences of the output periodic signal to occur. A number of second periodic occurrences of the output periodic signal is also counted in a selected time period. A speed of the moving member is calculated as a function of the time duration for the plurality of first periodic occurrences to occur and the number of second periodic occurrences to occur in the selected time period.

Abstract: A system and method for controlling energization of an electric motor (rotating or linear). The system and method includes producing a pulse-width modulated command signal to control switching devices that connect the motor to an energization source. A pulse-width modulated duty cycle value is formed as a function of the pulse-width modulated command signal. A leading current with respect to the phase angle of the back EMF is provided to the motor as a function comparing the pulse-width modulated duty cycle value with a selected threshold.

Abstract: A system controller for a controllable system having an inherent time delay includes a delay module that receives a command input and provides a first output signal delayed in time from the command input. A feed-forward module also receives the command input, or a function thereof, and provides a second output signal intended to drive the system to a desired state. A first summer receives the delayed output signal and a feedback signal from the controllable system. The first summer combines the delayed signal and the feedback signal to provide a third output signal. A compensator module receives the third output signal and provides a fourth output signal. A second summer receives the second output signal and the fourth output signal. The second summer combines the second output signal and the fourth output signal to provide an input signal for the controllable system.

Abstract: A method and apparatus for monitoring one or more parameters of a variable physical structure, such as liquid level, is disclosed. The method and apparatus includes an electrodynamic element placed in proximity to a monitored structure and exciting within said element an alternating electromagnetic field. The electromagnetic field should be at a frequency at which the electromagnetic field penetrates into the monitored structure and then variations of the electromagnetic field parameters are measured for the element caused by a variation in the structure. The exciting of the electrodynamic element is by an electromagnetic field in the form of at least one slowed electromagnetic wave having suitable energy distribution of the electric and magnetic fields for the measuring of the electromagnetic field parameters.

Abstract: A method and system for generating an improved nonlinear system model includes generating a linear system model and using a response therefrom to generate the nonlinear system model. A method and system for generating drive signals for a test system uses the improved nonlinear system model or a conventional nonlinear system model.

Abstract: A vehicle test apparatus having a rotationally supported steer member and a steer arm assembly including a steer arm operable coupled to the steer member and movable therewith. The steer arm is coupled to the steer member in a first position to form a forward steer arm connectable to a forward steer unit and orientable in a second position to form a rear steer arm connectable to a rear steer unit for front and rear steer testing. A steer actuator is coupled to the steer member and operable between forward and rear actuation modes for forward and rear steer testing.

Abstract: A loading assembly used in a vehicle spindle text fixture to apply a lateral force parallel to a spindle axis of a vehicle spindle includes a support frame and a wheel adapter housing mountable to the vehicle spindle. A pair of vertical struts are pivotally joined to the wheel adapter housing. A first actuator is operably coupled to the vertical struts to apply a force along a vertical axis substantially perpendicular to the spindle axis and substantially perpendicular to a longitudinal axis of the vehicle. A pair of lateral struts are provided. Each lateral strut is pivotally joined to one of the vertical struts. A second actuator is operably coupled to the lateral struts to apply a lateral force.