Abstract: In an exemplary embodiment, a test system is provided for testing a power steering system for a vehicle, the test system including a motor, one or more sensors, and a processor. The one or more sensors are configured to obtain sensor data pertaining to the motor. The processor is coupled to the one or more sensors and to the motor, and is configured to: determine, using the sensor data, a desired position of the motor for providing a desired amount of torque to the power steering system in order to reach one or more target behaviors: an inertia target, a spring target, a damper target, or a friction target for the power steering system; and provide instructions for the motor to move to the desired position for providing torque to the power steering system.

Abstract: In an exemplary embodiment, a test system is provided for testing a power steering system for a vehicle, the test system including a motor, one or more sensors, and a processor. The one or more sensors are configured to obtain sensor data pertaining to the motor. The processor is coupled to the one or more sensors and to the motor, and is configured to: determine, using the sensor data, a desired position of the motor for providing a desired amount of torque to the power steering system in order to reach one or more target behaviors: an inertia target, a spring target, a damper target, or a friction target for the power steering system; and provide instructions for the motor to move to the desired position for providing torque to the power steering system.

Abstract: A system and method for passively and actively monitoring and determining the location of at least one mechanical anomaly for a power steering system of a vehicle is disclosed. The system includes one or more processors and a memory coupled to the processors. The memory stores a baseline waveform and data comprising program code that, when executed by the one or more processors, causes the system to receive at least one excitation signal and at least one response signal. The power steering system creates the response signal in response to receiving the excitation signal. In response to receiving the excitation signal and the response signal, the system is caused to estimate the frequency response between the excitation signal and the response signal based on a fast Fourier transform (FFT) algorithm. The frequency response is represented by an estimated waveform.

Abstract: A system and method for determining a frequency response of a power steering system is disclosed including a steering assist motor configured to generate an assist torque about an axis of a steering shaft when activated. The method includes monitoring, by a controller, a torque transducer that measures a steering output torque of the steering shaft experienced during a first frequency sweep and a second frequency sweep. The method also includes determining, by the controller, a transfer function based on the steering output torque monitored during the first frequency sweep and the second frequency sweep, where the transfer function indicates the response by the power steering system.

Abstract: Methods and apparatus are provided for determining steering performance. The method includes: generating a torque disturbance signal; applying the torque disturbance signal to a torque command of the steering system; measuring a value of torque on the steering system; recording the measured value and a value associated with the torque disturbance signal; computing at least one performance metric of the steering system based on the recorded measured value and the recorded value associated with the torque disturbance signal; and selectively improving a steering system based on the at least one performance metric.

Abstract: A system and method for determining a frequency response of a power steering system is disclosed including a steering assist motor configured to generate an assist torque about an axis of a steering shaft when activated. The method includes monitoring, by a controller, a torque transducer that measures a steering output torque of the steering shaft experienced during a first frequency sweep and a second frequency sweep. The method also includes determining, by the controller, a transfer function based on the steering output torque monitored during the first frequency sweep and the second frequency sweep, where the transfer function indicates the response by the power steering system.

Abstract: A system and method include receiving, by an interface device, test information including a test message from testing equipment. The interface device is configured to interface between the testing equipment and a test specimen. The method also includes converting, by the interface device, the test information into at least one proprietary message. The proprietary message is proprietary to an original-equipment-manufacturer or integrator of the test specimen. The method also includes transmitting the at least one proprietary message to the test specimen. The test specimen is tested based on the at least one proprietary message.

Abstract: A system and method for passively and actively monitoring and determining the location of at least one mechanical anomaly for a power steering system of a vehicle is disclosed. The system includes one or more processors and a memory coupled to the processors. The memory stores a baseline waveform and data comprising program code that, when executed by the one or more processors, causes the system to receive at least one excitation signal and at least one response signal. The power steering system creates the response signal in response to receiving the excitation signal. In response to receiving the excitation signal and the response signal, the system is caused to estimate the frequency response between the excitation signal and the response signal based on a fast Fourier transform (FFT) algorithm. The frequency response is represented by an estimated waveform.

Abstract: Methods and apparatus are provided for determining steering performance. The method includes: generating a torque disturbance signal; applying the torque disturbance signal to a torque command of the steering system; measuring a value of torque on the steering system; recording the measured value and a value associated with the torque disturbance signal; computing at least one performance metric of the steering system based on the recorded measured value and the recorded value associated with the torque disturbance signal; and selectively improving a steering system based on the at least one performance metric.

Abstract: A method for characterizing a stick-slip condition in a steering system includes transmitting a periodic steering control signal to a rotary actuator to cause rotation of a steering shaft, through a torsion bar and inertia wheel, over a range of steering angles, and applying an axial force to a rack to resist rack displacement from a centered position. A steering torque output value is measured via a torque transducer. A control action is executed when a measured difference between a maximum value of a steering torque required to initiate rack motion/torque breakaway and a minimum value of the steering torque after breakaway for start-up or subsequent steering reversal exceeds a calibrated threshold. A system includes the rotary actuator, steering system, torque transducer, torsion bar, inertia wheel, linear actuator(s) providing an axial force along the rack axis to resist rack displacement from a centered position, and controller programmed as noted above.

Abstract: Methods and apparatus are provided for determining steering performance. The method includes coupling at least one load source to the steering system, and coupling a portion of the steering system to an angle input source. The method also includes outputting one or more control signals by a processor to the at least one load source to apply a load to the steering system and outputting one or more control signals by the processor to the angle input source to apply an input to the steering system. The method includes receiving torque data indicating a performance of the steering system based on the load applied to the steering system by the at least one load source and the input applied by the angle input source.

Abstract: A method for characterizing a stick-slip or stiction condition in an electrically-assisted steering system includes transmitting a first steering control signal from a controller to a rotary actuator as a periodic steering conditioning signal, receiving a second steering control signal via a steering assist motor throughout the test to electrically assist steering, transmitting a third steering control signal to the rotary actuator to cause alternate rotation of the steering shaft to a target angle rate at constant acceleration/deceleration, and measuring a steering torque output from the rotary actuator. A control action is executed when a difference in local maximum and minimum peak amplitudes of the steering torque output exceeds a calibrated threshold difference indicative of stiction. A system includes a rotary actuator, the steering system, a torque transducer operable for measuring a steering torque imparted to the steering shaft by the rotary actuator, and the controller noted above.

Abstract: A method for characterizing a stiction condition in a manual steering gear includes transmitting a steering input control signal to a rotary actuator, and rotating a steering shaft with constant acceleration, via the rotary actuator, in response to the steering input control signal. A steering output torque is determined while rotating the steering shaft with the constant acceleration, receiving the steering output torque via the controller, and executing a control action when a rate of the received steering output torque exceeds a threshold rate indicative of the stiction condition. A system includes a rotary actuator, a manual steering gear having a steering shaft connected to the rotary actuator, a torque transducer for measuring a steering output torque imparted to the steering shaft by the actuator, and a controller programmed as set forth above.

Abstract: A method for characterizing a stick-slip condition in a steering system includes transmitting a periodic steering control signal to a rotary actuator to cause rotation of a steering shaft, through a torsion bar and inertia wheel, over a range of steering angles, and applying an axial force to a rack to resist rack displacement from a centered position. A steering torque output value is measured via a torque transducer. A control action is executed when a measured difference between a maximum value of a steering torque required to initiate rack motion/torque breakaway and a minimum value of the steering torque after breakaway for start-up or subsequent steering reversal exceeds a calibrated threshold. A system includes the rotary actuator, steering system, torque transducer, torsion bar, inertia wheel, linear actuator(s) providing an axial force along the rack axis to resist rack displacement from a centered position, and controller programmed as noted above.

Abstract: A method for characterizing a stick-slip or stiction condition in an electrically-assisted steering system includes transmitting a first steering control signal from a controller to a rotary actuator as a periodic steering conditioning signal, receiving a second steering control signal via a steering assist motor throughout the test to electrically assist steering, transmitting a third steering control signal to the rotary actuator to cause alternate rotation of the steering shaft to a target angle rate at constant acceleration/deceleration, and measuring a steering torque output from the rotary actuator. A control action is executed when a difference in local maximum and minimum peak amplitudes of the steering torque output exceeds a calibrated threshold difference indicative of stiction. A system includes a rotary actuator, the steering system, a torque transducer operable for measuring a steering torque imparted to the steering shaft by the rotary actuator, and the controller noted above.

Abstract: A method for characterizing a stiction condition in a manual steering gear includes transmitting a steering input control signal to a rotary actuator, and rotating a steering shaft with constant acceleration, via the rotary actuator, in response to the steering input control signal. A steering output torque is determined while rotating the steering shaft with the constant acceleration, receiving the steering output torque via the controller, and executing a control action when a rate of the received steering output torque exceeds a threshold rate indicative of the stiction condition. A system includes a rotary actuator, a manual steering gear having a steering shaft connected to the rotary actuator, a torque transducer for measuring a steering output torque imparted to the steering shaft by the actuator, and a controller programmed as set forth above.

Abstract: Methods and apparatus are provided for determining steering performance. The method includes coupling at least one load source to the steering system, and coupling a portion of the steering system to an angle input source. The method also includes outputting one or more control signals by a processor to the at least one load source to apply a load to the steering system and outputting one or more control signals by the processor to the angle input source to apply an input to the steering system. The method includes receiving torque data indicating a performance of the steering system based on the load applied to the steering system by the at least one load source and the input applied by the angle input source.

Abstract: A method for characterizing steering gear reversal clunk noise in a steering system having a rack and a pinion gear, and electric power steering assist via a steering assist motor, includes transmitting a steering input angle control signal to a rotary actuator to rotate a steering shaft to a fixed steering angle with assist active. A linear actuator applies an axial force at a constant rate along a longitudinal axis of the rack. Axial rack acceleration is measured after imparting the axial force. A control action is executed when peak amplitude of the axial acceleration value exceeds a calibrated threshold axial acceleration value indicative of the clunk noise. A system includes the rotary actuator and steering system, a linear actuator for providing a calibrated axial apply force along the rack axis, an accelerometer for measuring an axial acceleration value of the rack, and the controller noted above.