Examples provide a trailer hitch system for connecting a tow vehicle and a trailer. Some examples of the system include a vehicle connector configured to be coupled to the tow vehicle and a chamber coupled to the vehicle connector. The chamber includes a center, an interior wall, and a valve for modulating a flow of hydraulic fluid within the chamber. A pin extends through the chamber and is configured to rotate within the chamber. A paddle is coupled to the pin and sized and shaped to sit substantially flush against the interior wall. The paddle is configured to push the hydraulic fluid in a first direction and a second direction through the valve. A trailer connector is coupled to the pin and configured to be coupled to the trailer.

An anti-jackknife steering system for an articulated bus is provided. A hydraulic turntable is used for actively generating a calculated force to balance the inertia of a front frame and a trailer frame. Consequently, the joint angle is adjusted to an optimal range, and the possibility of causing an oversteering event or a jackknife event is largely reduced. Moreover, a wheel brake device cooperates with the hydraulic turntable to assist in the steering action of the articulated bus on a snowy road. Consequently, while the articulated bus is driven on a slippery road, the possibility of causing collision is minimized.

Examples provide a trailer hitch system for connecting a tow vehicle and a trailer. Some examples of the system include a vehicle connector configured to be coupled to the tow vehicle and a chamber coupled to the vehicle connector. The chamber includes a center, an interior wall, and a valve for modulating a flow of hydraulic fluid within the chamber. A pin extends through the chamber and is configured to rotate within the chamber. A paddle is coupled to the pin and sized and shaped to sit substantially flush against the interior wall. The paddle is configured to push the hydraulic fluid in a first direction and a second direction through the valve. A trailer connector is coupled to the pin and configured to be coupled to the trailer.

An active steering system for an articulated bus is provided. In an assisted steering mode, a hydraulic turntable assists in the steering action of the articulated bus. While the articulated bus is linearly driven at a high speed or the lane-changing action is performed, the assisted steering mode can provide stable driving performance. In the assisted steering mode, a better steering trajectory is achieved while a cornering action of the articulated bus is performed. By collecting the information about the driving velocity, the position of the transmission gear and the position of the steering wheel, a steering force applied to the front frame and the trailer frame is calculated. Moreover, if the control unit judges that the angle of the hydraulic turntable is optimal, a locking force is generated to assure the optimal angle of the articulated bus. The assisted steering mode also supports the action of reversing the articulated bus. When the articulated joint is adjusted to an optimal trajectory, the articulated bus is reversed to the designated position.