A method for operating a motor vehicle having a four-wheel drive and a drive unit, which can be switched on and off during travel, wherein the motor vehicle is driven by a torque provided by the drive unit, and the initially disengaged four-wheel drive is switched on, including: determining at least one limit torque which, while the four-wheel drive is switched off, can be transmitted from at least one wheel of the motor vehicle driven by the drive unit to the ground surface upon which the motor vehicle is travelling, while the slip between the at least one wheel and the ground surface falls below a specifiable threshold value.

A method is described for computing a friction estimate between a road surface and a tire of a vehicle when the vehicle is in motion along a course, the tire being arranged on a steerable wheel of the vehicle, and the vehicle including two front wheels and two rear wheels and an axle rack pivotably attached to a linkage arm connected to the steerable wheel such that a translational motion of the axle rack causes the linkage arm to rotate about a kingpin element such that the linkage arm causes a turning motion of the steerable wheel. A corresponding system and vehicle are also described.

An arithmetic model generation system includes a sensor information acquisition unit, a tire force calculator, and an arithmetic model update unit. The sensor information acquisition unit acquires acceleration of a tire. The tire force calculator includes an arithmetic model for calculating tire force F based on the acceleration, and calculates the tire force F by inputting the acceleration acquired by the sensor information acquisition unit. The arithmetic model update unit compares tire axial force measured by the tire and the tire force F calculated by the tire force calculator, and updates the arithmetic model.

A system for modifying vehicle behavior based on data from a dynamically updated roadway coefficient of friction database. The system includes a roadway coefficient of friction database and an electronic computing device. The electronic computing device includes a first electronic processor that is configured to receive a current coefficient of friction and a location of a vehicle and depending on a criterion, replace, in the roadway coefficient of friction database, a previous coefficient of friction with the current coefficient of friction. The first electronic processor is also configured to receive a request for a coefficient of friction associated with a location and transmit the coefficient of friction associated with the location. Additionally, the system includes a plurality of vehicles each including a second electronic processor. Each second electronic processor is configured to perform a preventative measure based on the coefficient of friction received from the electronic computing device.

Systems and methods are shown for meeting wheel torque demand in a hybrid vehicle with an engine, a dual clutch transmission coupled to a driveline of the vehicle downstream of the engine, and an electric machine coupled to the driveline downstream of the dual clutch transmission. In one example, a method includes transferring transmission input torque through a clutch of the dual clutch transmission controlled to a first capacity, and, in response to a desired transmission input torque exceeding the capacity, increasing torque output of the electric machine coupled downstream of the dual clutch transmission to assist in meeting a wheel torque demand. In this way, a driver-requested increase in acceleration may be met under conditions where transmission input torque is limited by clutch capacity.

A control apparatus of a hybrid leaning vehicle includes: a travel mode request section that requests one travel mode selected from a plurality of travel modes including a first travel mode in which an engine is operated with a clutch disengaged and a second travel mode in which the engine is operated with the clutch engaged; and a travel mode setting section. When the travel mode request section requests the second travel mode during travel in the first travel mode, the travel mode setting section, upon determining that a shock accepting condition is satisfied, sets the second travel mode as the travel mode to be executed and, upon determining that the shock accepting condition is not satisfied, prohibits the second travel mode from being set as the travel mode to be executed.

A driving force control system for a vehicle configured to eliminate slippage of a wheel without changing a driving torque or a braking torque abruptly. The driving force control system comprises a drive unit and a controller. The drive unit includes a differential mechanism connected to a right wheel and a left wheel to distribute torque of a torque generating device, and a differential restricting device that restricts a differential rotation between the right wheel and the left wheel. The controller restricts a differential rotation between the right wheel and the left wheel less than a predetermined value by the differential mechanism. If a slip ratio of one of the wheels smaller than that of the other wheels is greater than an acceptable value, the controller executes a slip-eliminating control.

A fuel-saving control device equipped with: a surplus drive force calculation unit for calculating surplus drive force; a fuel-saving control unit for executing a fuel-saving control which lowers and corrects the indicated fuel injection amount according to the accelerator position when the surplus drive force reaches or exceeds a first threshold, and stopping the fuel-saving control when the surplus drive force falls below the first threshold; a vehicle position detection unit for detecting the vehicle position; a map information storage unit for storing map information; a road information identification unit for identifying the curvature radius and gradient of the road upon which travel is planned, on the basis of the vehicle position and the map information; and a flat/straight road determination unit for determining whether or not the road upon which travel is planned is a flat and straight road, on the basis of the curvature radius and gradient of the road upon which travel is planned. Therein, the fuel-saving control unit executes the fuel-saving control when the road upon which travel is planned is a flat and straight road.

An electronic controller (10) for a motor vehicle (100), the controller being configured to determine when at least one wheel (111, 112, 114, 115) has lost traction, wherein when the controller (10) determines that at least one wheel (111, 112, 114, 115) has lost traction the controller (10) is configured to provide an output to a driver indicative of the at least one wheel (111, 112, 114, 115) that has lost traction.

A method for controlling a propulsion system of a motor vehicle includes: optimizing both torque control and fuel economy during transient operating conditions; performing a steady state control enable function to identify when steady state operating conditions are present including: determining a commanded axle torque; obtaining a measured actual axle torque; and identifying when the commanded axle torque is substantially equal to the measured actual axle torque and outputting a signal; and further includes: directing the signal output from the control enable function to each of an integral action calculator and a Ym filter; performing an integral action calculation to identify an axle torque integral action; and setting a steady state flag when steady state operating conditions are present which fixes system variables directed to optimizing torque control, temporarily ceasing further optimization of torque control when the steady state flag is set.