Suspension based active force damping for a vehicle
An active damping system for an electric motor driven vehicle having spaced apart front wheels coupled to the vehicle by suspension components, includes a first sensor, a first actuator and a controller. The first sensor is coupled to one or both of a first front wheel or a suspension assembly for the first front wheel, and the first sensor provides an output indicative of a force on a component to which the first sensor is coupled. The first actuator is coupled to the vehicle and has a movable mass driven by the first actuator. The controller is configured to receive the output from the first sensor and the controller is configured, in response to at least an output from the first sensor that is beyond a threshold, to provide an output to the first actuator to displace the movable mass and at least partially damp vibrations in the vehicle.
1 . An active damping system for an electric motor driven vehicle having front wheels spaced apart in a cross-car direction and coupled to the vehicle by suspension components, and rear wheels spaced from the front wheel in a fore-aft direction, the system comprising:
a first sensor coupled to one or both of a first front wheel or a suspension assembly for the first front wheel, the first sensor providing an output indicative of a force on a component to which the first sensor is coupled;
a first actuator having a housing rigidly coupled to a vehicle frame at a location spaced in one or both of the fore-aft direction and the cross-car direction from the first front wheel and the suspension assembly for the first front wheel, the first actuator having a movable mass driven by the first actuator, the movable mass includes a magnet and a ferromagnetic component coupled to the magnet, and the first actuator includes a wire coil; and
a controller configured to receive the output from the first sensor and the controller is configured, in response to at least an output from the first sensor that is beyond a threshold, to provide electricity to the wire coil of the first actuator to displace the movable mass and apply forces directly to the vehicle frame at the location to at least partially damp vibrations in the vehicle due to force provided to the vehicle frame by the movement of the movable mass relative to the vehicle frame.
2 . The system of claim 1 which also comprises a second sensor coupled to one or both of a second front wheel or a suspension assembly for the second front wheel, the second sensor providing an output to the controller where the output is indicative of a force on a component to which the second sensor is coupled, and a second actuator coupled to the vehicle and having a movable mass driven by the second actuator, and wherein the controller is configured to receive the output from the second sensor and the controller is configured, in response to at least an output from the second sensor that is beyond a threshold, to provide an output to the second actuator to displace the movable mass and at least partially damp vibrations in the vehicle.
3 . The system of claim 2 wherein the controller is configured to provide an output to either or both of the first actuator and the second actuator in response to an output from at least one of the first sensor and the second sensor that is beyond a threshold.
4 . The system of claim 1 , wherein the wire coil surrounds the movable mass, and when electricity is provided to the wire coil, the movable mass is displaced by an electromagnetic field of the first actuator.
5 . The system of claim 1 , wherein the magnet is a rare earth magnet.
6 . The system of claim 1 wherein the first actuator is coupled to the vehicle frame at a location between a rear of the vehicle and the first sensor.
7 . The system of claim 1 which also includes a vehicle speed sensor having an output communicated with the controller, and wherein the output from the controller is a function of the output from the first sensor and from the vehicle speed sensor.
8 . The system of claim 1 which includes a tire pressure sensor having an output communicated with the controller, and wherein the output from the controller is a function of the output from the first sensor and from the tire pressure sensor.
9 . The system of claim 1 which includes one or more sensors that provide an indication of vehicle weight, wherein the output of the one or more sensors is communicated with the controller, and wherein the output from the controller is a function of the output from the first sensor and from the one or more sensors.
10 . The system of claim 1 which also includes a second sensor associated with the actuator and arranged to provide an output to the controller indicative of a force on the actuator or an area adjacent to the actuator.
11 . The system of claim 1 wherein the housing is fixed to the vehicle frame at a location spaced rearwardly from the first front wheel or the suspension assembly for the first front wheel such that forces provided from the first actuator, as a result of movement of the movable mass, are provided directly to the vehicle frame and are not provided directly to the first front wheel or the suspension assembly for the first front wheel.
12 . The system of claim 11 wherein the housing is coupled to the vehicle frame so that the natural frequency of the first actuator when connected to the vehicle frame is greater than the highest operating frequency of the actuator.
13 . The system of claim 11 wherein the first actuator includes a shaft coupled to the housing, and wherein the movable mass includes a passage through which the shaft is received and so that movement of the movable mass is guided by the shaft.
14 . A method of controlling an actuator to damp forces in a vehicle, comprising the steps of:
sensing a force with a first sensor coupled to one or both of a first front wheel or a suspension assembly for the first front wheel, wherein the vehicle includes a second front wheel spaced from the first front wheel in a cross-car direction, and the vehicle includes two rear wheels spaced rearwardly from the first front wheel and the second front wheel in a fore-aft direction;
communicating the force with a controller; and
providing an output from the controller, at least when the force exceeds a threshold, to a first actuator coupled to a vehicle frame at a location spaced rearwardly from the first front wheel and the suspension assembly for the first front wheel and having a movable mass driven by the first actuator, whereby the output from the controller causes the first actuator to displace the movable mass and at least partially damp vibrations in the vehicle frame by providing force from the first actuator, as a result of movement of the movable mass, directly to the vehicle frame at the location.
15 . The method of claim 14 wherein the output from the controller is a function of the output from the first sensor and from one or more sensors indicative of a vehicle speed, tire pressure, vehicle steering angle, and vehicle weight, and wherein the output from the controller is provided to offset forces in the vehicle frame associated with a rear wheel of the vehicle encountering a road condition that the first front wheel has already encountered.
16 . The method of claim 14 wherein the output from the controller is adjustable in an open loop control scheme based upon an output sent to the controller from a second sensor associated with the first actuator.
17 . The method of claim 16 wherein, if the output from the second sensor indicates a force above a threshold exists at the second sensor after the first actuator has been actuated, then the controller provides another output to actuate the first actuator again.
18 . The method of claim 14 wherein a second sensor coupled to one or both of the second front wheel or a suspension assembly for the second front wheel, and which includes communicating the output from the second sensor with the controller and wherein the controller provides an output to the first actuator as a function of the output from both the first sensor and the second sensor.
19 . The method of claim 18 which includes a second actuator and wherein the controller provides an output to the second actuator to actuate the second actuator as a function of the output from both the first sensor and the second sensor.
20 . The method of claim 19 wherein the output provided to the second actuator is different than the output provided to the first actuator.