A method is provided for controlling a hydraulic hybrid vehicle, the hydraulic hybrid vehicle including: a first pair of wheels and a second pair of wheels; an internal combustion engine connected to the first pair of wheels for propelling the hydraulic hybrid vehicle; and a hydraulic propulsion system including a first hydraulic machine connected to the second pair of wheels, the method including the steps of; receiving a signal indicative of a driving condition, including vehicle speed, of the hydraulic hybrid vehicle; comparing the vehicle speed of the driving condition of the hydraulic hybrid vehicle with an upper predetermined threshold speed limit; determining if the vehicle speed of the driving condition is higher than the upper predetermined threshold speed limit; and when the vehicle speed is higher than the upper predetermined threshold speed determining, based on the driving condition, control parameters for operating the first hydraulic machine; and controlling the control parameters of the first hydraulic machine for operating the first hydraulic machine. The invention also relates to a control unit and a hydraulic hybrid vehicle.

A propulsion arrangement for a self-powered dolly vehicle unit, the propulsion arrangement comprising a first electric machine, a second electric machine, a gearbox, and an open differential for driving first and second wheels of a driven axle, wherein the first and second electric machines are arranged in parallel and connected to the open differential via the gearbox at respective gear ratios.

A propulsion arrangement for a self-powered dolly vehicle unit, the propulsion arrangement comprising a first electric machine, a second electric machine, a gearbox, and an open differential for driving first and second wheels of a driven axle, wherein the first and second electric machines are arranged in parallel and connected to the open differential via the gearbox at respective gear ratios.

The vehicle system can include: a set of vehicle couplings (e.g., a tractor interface, a trailer interface, etc.); a chassis, a battery pack, an electric powertrain, a sensor suite, and a controller. The modular vehicle system can optionally include landing gear, a suspension, and any other suitable set of components. The vehicle system functions to structurally support and/or tow a trailersuch as a Class 8 semi-trailerand/or to augment/supplement a tractor propulsive capability (e.g., via a diesel/combustion engine) with a supplementary electric drive axle(s).

The vehicle system can include: a set of vehicle couplings (e.g., a tractor interface, a trailer interface, etc.); a chassis, a battery pack, an electric powertrain, a sensor suite, and a controller. The modular vehicle system can optionally include landing gear, a suspension, and any other suitable set of components. The vehicle system functions to structurally support and/or tow a trailersuch as a Class 8 semi-trailerand/or to augment/supplement a tractor propulsive capability (e.g., via a diesel/combustion engine) with a supplementary electric drive axle(s).

A method for controlling the driving of at least one drive axle on a trailer of a traction vehicle-trailer combination includes determining a target drive power for the drive axle of the trailer as a function of a distribution of contact forces on the trailer or on the traction vehicle, or as a function of a traction drive power for the traction vehicle. The method further includes providing drive control signals for controlling an electrical drive for the drive axle of the trailer. The drive control signals are derived from the determined target drive power.

A method for controlling the driving of at least one drive axle on a trailer of a traction vehicle-trailer combination includes determining a target drive power for the drive axle of the trailer as a function of a distribution of contact forces on the trailer or on the traction vehicle, or as a function of a traction drive power for the traction vehicle. The method further includes providing drive control signals for controlling an electrical drive for the drive axle of the trailer. The drive control signals are derived from the determined target drive power.