A system includes an internal combustion engine including a crankshaft, a transmission including a transmission shaft, an axle, and a first electric machine rotatably coupled at least one of the crankshaft, the transmission shaft, and the axle. The first electric machine is configured to deliver rotational torque, and to generate electrical energy. The system includes an electrically-assisted turbomachine including a second electric machine configured to deliver rotational torque, and to generate electrical energy. The system includes a hybrid propulsion traction battery electrically coupled to the first and second electric machines. The hybrid propulsion traction battery is configured to deliver electrical energy to the first electric machine, and to receive electrical energy from the first and second electric machines. The system includes an electronic control unit configured to control electrical energy supplied to the first electric machine, and to control electrical energy supplied to the hybrid propulsion traction battery.

In one embodiment, a method for controlling engine braking is disclosed. The method includes determining an amount of brake pressure being applied by a vehicle traveling on a road. The method includes determining a current velocity of the vehicle, wherein a transmission of the vehicle is operating using a first gear of a plurality of gears. The method includes, according to the amount of brake pressure and the current velocity of the vehicle, determining a road grade threshold for a second gear of the plurality of gears. The method includes determining a grade of the road. The method includes determining that the determined grade of the road satisfies the road grade threshold for the second gear of the vehicle. The method includes, in response to the determination, causing the transmission of the vehicle to operate in the second gear of the plurality of gears.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, an actual total number of deactivated cylinders may be adjusted to control driveline braking. The driveline braking may be controlled in a towing mode, a hill descent mode, and during normal driving conditions.

A propulsion system, control system, and method use model predictive control systems to generate a plurality of sets of possible command values and determine a cost for each set of possible command values. The set of possible command values that has the lowest cost is determined and defined as a selected set of command values. In some circumstances, the MPC-determined command value may be replaced by another transmission ratio command based on override inputs. Minimum and maximum transmission ratios are determined based on the override inputs, and a constrained (or arbitrated) transmission ratio is determined therefrom. The constrained or arbitrated transmission ratio is used to determine whether to apply an MPC-determined transmission ratio or a transmission ratio based on the arbitrated transmission ratio to determine an ultimate commanded transmission ratio. Pressure(s) are commanded to a transmission pulley assembly, which is configured to implement the ultimate commanded transmission ratio.

A method and system of determining the instant gradient of a road, taking into account positive and negative drive torque, may be used to select one of a plurality of shift maps for a vehicle automatic transmission. The invention takes into account vehicle retardation due to braking, and permits consistent adoption of a shift map appropriate to the instant gradient.

A hybrid electric vehicle includes a combustion engine, and an electric machine and storage battery coupled to one or more controller(s) configured to respond to various signals from a driver and vehicle components. In response, such controller(s) enable an automatic or auto ICE start stop capability that is managed for optimal HEV lifecycle operation, and fuel economy and efficiency. The controller(s) automatically start and stop the ICE in response to one or more of a torque demand signal, a vehicle speed signal, a steering torque power signal, and a brake signal. The controller(s) inhibit automatic stop of ICE responsive to the steering torque power exceeding a stop threshold, and in contrast initiate or enable automatic start responsive to the steering torque power exceeding a start threshold. The start threshold is calibrated and adjusted to exceed the stop threshold by a stability factor that is predetermined and/or adjusted by the controller(s).

A method for controlling the speed of a work vehicle during downhill operation may include controlling an operation of at least one of an engine or a transmission of a work vehicle so as to maintain the work vehicle operating at a requested speed and identifying an operating condition of the work vehicle that provides an indication that the work vehicle is traveling downhill. In addition, the method may include determining whether at least one pre-condition for downshifting the transmission from a current gear ratio to a downshift gear ratio is satisfied when the operating condition indicates that the work vehicle is currently traveling downhill. Moreover, when it is determined that the pre-condition(s) is satisfied, the method may include controlling the operation of the transmission such that the transmission is downshifted from the current gear ratio to the downshift gear ratio.

A hybrid electric vehicle includes a combustion engine, and an electric machine and storage battery coupled to one or more controller(s) configured to respond to various signals from a driver and vehicle components. In response, such controller(s) enable an automatic or auto ICE start stop capability that is managed for optimal HEV lifecycle operation, and fuel economy and efficiency. The controller(s) automatically start and stop the ICE in response to one or more of a torque demand signal, a vehicle speed signal, a steering torque power signal, and a brake signal. The controller(s) inhibit automatic stop of ICE responsive to the steering torque power exceeding a stop threshold, and in contrast initiate or enable automatic start responsive to the steering torque power exceeding a start threshold. The start threshold is calibrated and adjusted to exceed the stop threshold by a stability factor that is predetermined and/or adjusted by the controller(s).

A method for controlling the speed of a work vehicle during downhill operation may include controlling an operation of at least one of an engine or a transmission of a work vehicle so as to maintain the work vehicle operating at a requested speed and identifying an operating condition of the work vehicle that provides an indication that the work vehicle is traveling downhill. In addition, the method may include determining whether at least one pre-condition for downshifting the transmission from a current gear ratio to a downshift gear ratio is satisfied when the operating condition indicates that the work vehicle is currently traveling downhill. Moreover, when it is determined that the pre-condition(s) is satisfied, the method may include controlling the operation of the transmission such that the transmission is downshifted from the current gear ratio to the downshift gear ratio.

Systems and methods for assessing runway conditions are disclosed. The system may comprise a brake control unit having an internal inertial sensor. The brake control unit may be configured to calculate a runway coefficient of friction to assess surface conditions of the runway. The brake control unit may monitor braking in an aircraft to detect a skid condition. In response to detecting the skid condition, the brake control unit may calculate an aircraft deceleration of the aircraft with the inertial sensor. The brake control unit may estimate the runway coefficient of friction based on the aircraft deceleration, an aerodynamic drag force of the aircraft, and a thrust reverse force of the aircraft.