Semi active suspension control methods using skyhook and endstop control

A method of controlling a damping force of a seat damper positioned between a seat and a base, the seat damper having a seat controller providing control thereto, the method comprising:

• measuring and calculating a plurality of input values, the plurality of input including the steps of:
• measuring an absolute acceleration (aabs) of the seat or base and generating an acceleration signal;
• measuring an unscaled relative displacement (xrel_unscaled) of the seat relative to the base and generating a displacement signal;
• calculating a maximum unscaled displacement (xmax_unscaled) and a minimum unscaled displacement (xmin_unscaled) from an AutoCalibration subprocess;
• calculating a scaled relative displacement (xrel_scaled), a maximum scaled displacement (xmax_scaled), and a minimum scaled displacement (xmin_scaled) using a standardized scaling subprocess;
• calculating an absolute velocity (Vabs_seat) of the seat and a relative velocity (Vrel) of the seat relative to the base from a signal processing subprocess using the absolute acceleration (aabs) and the scaled relative displacement (xrel_scaled);
• using the plurality of input values simultaneously determining a maximum endstop control signal (uES) and a skyhook control signal (uskyhook), wherein the maximum endstop control signal (uES) is determined by simultaneously running an absolute ellipse endstop control (EEC) subprocess generating an absolute EEC endstop control signal (CtrlEllipse_abs), a relative EEC subprocess generating a relative EEC endstop control signal (CtrlEllipse_rel), and an ESO2 endstop control subprocess generating an endstop control signal (CtrlESO2), wherein the maximum of the three is selected as the maximum endstop control signals (LES), wherein the skyhook control signal (Ctrlskyhook) is determined by running a skyhook control subprocess and generating a skyhook control signal (Ctrlskyhook) and running a rising edge filter subprocess on the skyhook control signal (Ctrlskyhook);
• aggregating the maximum endstop control signal (uES) and the skyhook control signal (uskyhook) to determine a desired seat performance by testing whether a sum of the maximum endstop control signal (uES) and the skyhook control signal (uskyhook) provides the desired seat performance, or a maximum between the maximum endstop control signal (uES) or the skyhook control signal (uskyhook) provides desired seat performance;
• generating a damping force control signal (uCtrl) based upon the desired seat performance;
• and
• controlling the seat damper.