Abstract: Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.

Abstract: Methods and systems are described for establishing high-accuracy absolute landmarks that can be used to locate a vehicle's location during a vehicle/HAAL interaction event in some embodiments. Comparing that information with GNSS satellite data allows GNSS satellite errors to be determined and either used by a first vehicle and/or conveyed to other vehicles in the region in some embodiments. Methods and systems are also described for obtaining effectively continuous values of intermittently measured road surface parameters that are determined over time by discrete measurements by systems in a plurality of vehicles in some embodiments.

Abstract: Localization systems, including road surface-based localization systems, are disclosed that may work in conjunction with less precise systems, such as GPS, to accurately locate a vehicle on a road segment. Methods and apparatus are disclosed for the identification and selection of landmarks, including road surface-based landmarks.

Abstract: Active suspension actuator systems including an actuator with a compression volume and an extension volume are described. In some embodiments, the system includes one or more flow control devices in fluid communication with the compression volume and/or the extension volume of the actuator. In some instances, a flow control device may include a pressure balanced blow-off valve (PBOV). In some embodiments, the system includes a high capacity bidirectional base valve. In some embodiments, two or more flow control devices cooperate to, for example, damp low amplitude oscillations in the extension and/or compression volumes, and to allow the build-up of pump generated differential pressures while discharging rapid road induced differential pressure spikes between the extension and compression volumes.

Abstract: In one embodiment, one or more suspension systems of a vehicle may be used to mitigate motion sickness by limiting motion in one or more frequency ranges. In another embodiment, an active suspension may be integrated with an autonomous vehicle architecture. In yet another embodiment, the active suspension system of a vehicle may be used to induce motion in a vehicle. The vehicle may be used as a testbed for technical investigations and/or as a platform to enhance the enjoyment of video and/or audio by vehicle occupants. In some embodiments, the active suspensions system may be used to perform gestures as a means of communication with persons inside or outside the vehicle. In some embodiments, the active suspensions system may be used to generate haptic warnings to a vehicle operator or other persons in response to certain road situations.

Abstract: Integrated multiple actuator electro-hydraulic systems as well as their methods of use are described. Depending on the particular application, the integrated electro-hydraulic systems may exhibit different frequency responses and/or may be integrated into a single combined unit.

Abstract: A method of on-demand energy delivery to an active suspension system is disclosed. The suspension system includes an actuator body, a hydraulic pump, an electric motor, a plurality of sensors, an energy storage facility, and a controller. The method includes disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.

Abstract: Methods and apparatus are disclosed for adjusting the front to rear ratio of roll damping and/or roll stiffness in a vehicle based on vehicle yaw rate and/or the rate of change of steering wheel angle. Also disclosed are methods and apparatus for dynamically adjusting one or more suspension system control parameters based on one or more of steering wheel angle, rate of change of steering wheel angle and yaw rate.

Abstract: In some embodiments, a rapid-response active suspension system controls suspension force and position for improving vehicle safety and drivability. The system may interface with various sensors that detect safety critical vehicle states and adjust the suspension of each wheel to improve safety. Pre-crash and collision sensors may notify the active suspension controller of a collision and the stance may be adjusted to improve occupant safety during an impact while maintaining active control of the wheels. Wheel forces may also be controlled to improve the effectiveness of vehicle safety systems such as ABS and ESP in order to improve traction. Also, bi-directional information may be communicated between the active suspension system and other vehicle safety systems such that each system may respond to information provided to the other.

Abstract: A regenerative shock absorber that include a housing and a piston that moves at least partially through the housing when the shock is compressed or extended from a rest position. When the piston moves, hydraulic fluid is pressurized and drives a hydraulic motor. The hydraulic motor, in turn, drives an electric generator that produced electric energy. The electric energy may be provided to a vehicle, among other things. The regenerative shock absorber may also provide ride performance that comparable to or exceeds that of conventional shock absorbers.

Abstract: A method of terrain-based localization of a vehicle is provided. The method may include determining the vehicle is within a threshold distance of a road segment end point and comparing a measured road profile to a reference road profile associated with the road segment. A method of identifying a track (e.g., a lane) of a road segment road profile is provided. The method may include determining if a number of stored road profiles exceeds a threshold number of road profiles and identifying one or more clusters in the stored road profiles if the threshold number is exceeded.

Abstract: System and method for improving braking efficiency by increasing the magnitude of a frictional force between a tire of a vehicle wheel and a road surface. Braking efficiency may be improved by controlling the normal force applied on the wheel, with an active suspension actuator, based on the wheel's slip ratio.

Abstract: An active suspension system is configured in a strut arrangement. The active suspension system comprises a hydraulic actuator and a hydraulic pump/electric motor assembly, wherein the actuator movement is preferably in lockstep with the hydraulic motor-pump and electric motor-generator combination. Torque in the electric motor is instantaneously controlled by a controller to create an immediate force change on the hydraulic actuator. The hydraulic actuator is configured so that it can be used as a strut whereby the actuator has sufficient structural rigidity to carry the applied suspension loads while capable of supplying damper forces in at least three quadrants of the force velocity graph of the suspension actuator operation. Embodiments disclosed include low cost active suspension systems for a MacPherson strut application.

Abstract: Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.

Abstract: Disclosed embodiments are related to suspension systems including dampers and suspension actuators and related methods of control for mitigating the effects of potholes and other road surface discontinuities.

Abstract: In one embodiment, one or more suspension systems of a vehicle may be used to mitigate motion sickness by limiting motion in one or more frequency ranges. In another embodiment, an active suspension may be integrated with an autonomous vehicle architecture. In yet another embodiment, the active suspension system of a vehicle may be used to induce motion in a vehicle. The vehicle may be used as a testbed for technical investigations and/or as a platform to enhance the enjoyment of video and/or audio by vehicle occupants. In some embodiments, the active suspensions system may be used to perform gestures as a means of communication with persons inside or outside the vehicle. In some embodiments, the active suspensions system may be used to generate haptic warnings to a vehicle operator or other persons in response to certain road situations.

Abstract: A method of on-demand energy delivery to an active suspension system is disclosed. The suspension system includes an actuator body, a hydraulic pump, an electric motor, a plurality of sensors, an energy storage facility, and a controller. The method includes disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.

Abstract: A method of on-demand energy delivery to an active suspension system comprising an actuator body, hydraulic pump, electric motor, plurality of sensors, energy storage facility, and controller is provided. The method comprises disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.

Abstract: In some embodiments, a rapid-response active suspension system controls suspension force and position for improving vehicle safety and drivability. The system may interface with various sensors that detect safety critical vehicle states and adjust the suspension of each wheel to improve safety. Pre-crash and collision sensors may notify the active suspension controller of a collision and the stance may be adjusted to improve occupant safety during an impact while maintaining active control of the wheels. Wheel forces may also be controlled to improve the effectiveness of vehicle safety systems such as ABS and ESP in order to improve traction. Also, bi-directional information may be communicated between the active suspension system and other vehicle safety systems such that each system may respond to information provided to the other.

Abstract: Integrated multiple actuator electro-hydraulic systems as well as their methods of use are described. Depending on the particular application, the integrated electro-hydraulic systems may exhibit different frequency responses and/or may be integrated into a single combined unit.