Abstract: Systems and methods for calibrating a solid-imaging system (10) are disclosed. A calibration plate (110) having a non-scattering surface (140) with a plurality (150) of light-scattering fiducial marks (156) in a periodic array is disposed in the solid-imaging system. The actinic laser beam (26) is scanned over the fiducial marks, and the scattered light (26S) is detected by a detector (130) residing above the calibration plate. A computer control system (30) is configured to control the steering of the light beam and to process the detector signals (SD) so as to measure actual center positions (xA, yA) of the fiducial marks and perform an interpolation that establishes a calibrated relationship between the angular positions of the mirrors and (x,y) locations at the build plane (23). The calibrated relationship is then used to steer the laser beam in forming a three-dimensional object (50).

Abstract: Systems and methods for calibrating a solid-imaging system (10) are disclosed. A calibration plate (110) having a non-scattering surface (140) with a plurality (150) of light-scattering fiducial marks (156) in a periodic array is disposed in the solid-imaging system. The actinic laser beam (26) is scanned over the fiducial marks, and the scattered light (26S) is detected by a detector (130) residing above the calibration plate. A computer control system (30) is configured to control the steering of the light beam and to process the detector signals (SD) so as to measure actual center positions (xA, yA) of the fiducial marks and perform an interpolation that establishes a calibrated relationship between the angular positions of the mirrors and (x,y) locations at the build plane (23). The calibrated relationship is then used to steer the laser beam in forming a three-dimensional object (50).

Abstract: In one embodiment, a vehicle braking system, for delivering pressurized air to a brake chamber to achieve a desired braking response, includes an air-pressure controlled relay valve for delivering the pressurized air to the brake chamber. A solenoid receives a variable control input pressure and delivers the control input pressure to the relay valve as a function of a state of the solenoid. An ECU controls the solenoid according to a control model for delivering the pressurized air to the brake chamber and achieving the desired braking response.

Abstract: A roll stability control system for a pneumatically operated vehicle brake system is implemented using simpler ABS hardware rather than more complex EBS hardware. For each brake chamber or channel, two 3/2 solenoid controlled valves are used. An ECU is operative to control the solenoids. The ECU is preferably operative to provide a selected delivery pressure to the brake chamber without measurement of delivery pressure to the brake chamber. Supply air is provided at a known pressure to a first solenoid controlled valve that is associated with the brake chamber; the amount of time of energization and de-energization of the first valve that is needed to provide an output therefrom of a given pressure, is calculated; and the first valve is energized and de-energized for the calculated times, thereby to cause a low-pressure test pulse to be provided to the brake chamber.