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 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 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 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.

Abstract: A welding head including upper and lower probe members and probe pin. The upper and lower probe members are independently actuatable and biased to follow the profile of a workpiece and supply a balance load to opposed surfaces of a workpiece during welding operation.

Abstract: A motion control system includes an inverter adapted to receive electrical power at a first DC voltage level and selectively provides power to a motor. A first DC--DC converter receives electrical power at the first DC voltage level and provides electrical power at a second DC voltage level. A second DC--DC converter receives electrical power at the second DC voltage level and provides electrical power at a third DC voltage level. A controller receives electrical power at the third DC voltage level and provides control signals to the inverter. A switching circuit is connectable to a second source of power and provides electrical power to the second DC--DC converter when the second DC voltage is less than a selected threshold.

Abstract: A material testing apparatus for applying selected force and moment loads to a test specimen includes a base assembly coupleable to the test specimen. The base assembly includes a support member and a first load generating mechanism adapted to apply a first load to the test specimen. A reaction structure reacts the first load applied to the test specimen. The reaction structure includes a reaction support joined to the support member. A moveable head is coupleable to the test specimen and is moveable relative to the reaction support. A second load generating mechanism is coupled to the moveable head and the reaction support. The second load generating mechanism is adapted to apply selected loads to the test specimen in at least two degrees of freedom.

Abstract: A load cell body for measuring components of force and moment in plural direction includes an integral assembly having a rigid central hub and a rigid annular ring concentric with the central hub. At least three radial tubes extends radially along corresponding longitudinal axes from the central hub to the annular ring. Flexure members join the radial tubes to the annular ring. Each flexure member is compliant for displacement of each corresponding radial tube along the corresponding longitudinal axis. As a load cell, a strain sensor mounted on each radial tube measures strain therein.

Abstract: A load transducer adapted to measure a load force applied to a load anvil. The load transducer including a base and a relatively rigid bridge coupled to the base and load anvil to floatably support the load anvil so that the load anvil moves relative to the rigid base proportional to an applied load. The transducer including a sealable chamber enclosed by surfaces of the load anvil, bridge and base and adapted to be filled with a flowable medium within the sealed chamber.

Abstract: A load cell for sensing forces or moments with respect to an orthogonal coordinate system includes a load cell body and a plurality of sensing circuits. The load cell body includes a rigid central member, a rigid annular ring and a plurality of radial members extending radially and joining the central member to the annular ring. A plurality of sensing circuits are mounted to the plurality of radial members. Each radial member includes a first sensing circuit providing a first output signal responsive to a first force exerted between the central member and the annular ring through the corresponding radial member in a first direction. Each radial member also includes a second sensing circuit providing a second output signal responsive to a second force exerted between the central member and the annular ring through the corresponding radial member in a second direction, wherein the second direction is substantially perpendicular to the first direction.

Abstract: An electromagnetic actuator includes an actuator rod having a plurality of magnetic assemblies disposed about a longitudinal axis of the actuator rod. Each plurality of magnetic assemblies develops alternating magnetic flux along the longitudinal axis. The electromagnetic actuator further includes a plurality of stator windings secured to a support structure and disposed about the longitudinal axis. Each stator winding has a pole facing a portion of one of the plurality of magnetic assemblies and the longitudinal axis.

Abstract: A restraint device for joining a first member to a second member and controlling relative movement of the first member with respect to the second member includes a rigid center member and a rigid annular member. The rigid annular member is concentrically disposed about the center member with respect to a common reference axis. A flexible continuous band is disposed concentrically between the center member and the annular member. The flexible continuous band joins the center member to the annular member at spaced-apart locations. The flexible continuous band is substantially rigid for moments about the common reference axis, yet compliant in other directions.

Abstract: A shock absorber includes a housing having a chamber and a piston slidably disposed in the chamber. A piston rod is connected to the piston and extends out of the housing. The piston rod includes a bore extending longitudinally therein. A magnetostrictive transducer provides an output signal indicative of the piston with respect to the housing. The magnetostrictive transducer includes a magnetostrictive waveguide disposed in the bore and a magnet joined to the housing that is operably coupled to the magnetostrictive waveguide.

Abstract: A test specimen holder for holding a test specimen in a material testing machine that applies force loads to the test specimen includes a base member having a first end coupleable to the material testing machine and a second end remote from the first end. A longitudinal axis extends from the first end to the second end. A body member extends from the second end to the first end and includes an aperture disposed on the longitudinal axis for receiving the test specimen. A displacement device displaces the body member relative to the base member substantially parallel to the longitudinal axis.

Abstract: A method of splicing the platen component of a linear stepper motor to extent its range of travel for various applications is disclosed. In a linear stepper motor the so-called forcer or armature component moves linearly along the platen or stator in the manner of a track assuming discrete locations in response to the state of the electrical current in the field windings of the forcer. Conventional machining equipment limits the maximum length of the platen that can be produced for such a motor. Because various industrial applications demand an extended length of the platen component, the splicing method enables two or more platen components to be arranged in an end-to-end relation while maintaining positional accuracy, preventing air loss from the air bearings typically utilized with such a motor, and maintaining the magnetic flux path necessary for proper operation of the forcer component of the motor.