Abstract: Vehicle control system and method in which restrictions on travel of the vehicle are determined based on an indication of the visibility of a driver and information about objects moving in a direction opposite to the direction of travel of the vehicle are considered. The travel restrictions include preventing a passing maneuver on a two-lane road when an oncoming vehicle precludes safely initiating or completing an already-initiated passing maneuver. A warning system is provided to warn a driver about the travel restrictions so that the driver will, hopefully, not attempt an unsafe maneuver.

Abstract: The utilization in a vehicle of the third derivative of rotational speed differences to enable early detection of the likely development or actual initiation of a condition involving wheel slip or loss of traction between the wheel and the surface over which it is traveling and to provide information to means to prevent the development of or reduce, inhibit, limit, eliminate, or control that condition is materially superior to the previously-disclosed methods intended for those purposes. The utilization of the third derivative of rotational speed differences for the indicated purposes produces highly useful and unexpected results and effectively addresses the problem of the detection of slip or loss of traction by means of a method of analysis not previously recognized or applied to that problem.

Abstract: In order to minimize a calculation load and surely obtain a maximum adhesion torque, estimated adhesion torques are always stored, an maximum value is obtained from the stored plural estimated adhesion torques immediately before slip/skid is detected when detecting the slip/skid, and the maximum value is set as a maximum adhesion torque. The maximum adhesion torque immediately before the slip/skid is detected is compared with a value of the estimated adhesion torque when the slip/skid is detected. When the calculated value exceeds a threshold value, it is determined as a condition where an adhesion coefficient drastically drops, and a suppression/return ratio of the torque is switched to a lower value than that under a condition where the adhesion coefficient does not drastically drop. The value of the torque at the time of suppression or return is set to a smaller value to surely suppress the slip/skid.

Abstract: A vehicle behavior control apparatus is equipped with a slip angle detector that detects a slip angle of a vehicle, a control amount calculation portion that calculates a control amount from the slip angle detected by the slip angle detector, a derivative of the slip angle, and a second order derivative of the slip angle, and a control portion that executes a behavior control for the vehicle based on the calculated control amount.

Abstract: When a rear wheel total drive force is smaller than a rear wheel drive force difference and the rear wheel drive force difference cannot be accomplished by dividing the rear wheel total drive force between the left and right rear wheels, an inside wheel target drive force is not set to 0 and an outside wheel target drive force is not set to. Instead, the inside wheel target drive force is set to a default drive force that is a minimum value required to prevent a three-wheel drive state from occurring, and the outside wheel target drive force is set a value equal to the sum of the default drive force and the rear wheel drive force difference, which is a value with which the rear wheel drive force difference can be achieved under the condition of the inside wheel target drive force being equal to the default drive force.

Abstract: A method for ascertaining a wheel reference speed of a wheel of a vehicle having a hydrostatic drive which uses a transfer medium, the hydrostatic drive acting at least on the one wheel, and the hydrostatic drive having an oscillating motor which may be swiveled to a pumping mode via which a torque may be applied to the wheel, and a wheel speed sensor for detecting the particular wheel speed being situated near the wheel, and the oscillating motor being appropriately adjusted while the wheel speed sensor ascertains the wheel reference speed in order to allow resistance-free flow of the transfer medium through the oscillating motor. The exemplary embodiments and/or exemplary methods of the present invention further relates to a device having arrangements for carrying out the method, and configured as a hydraulic drive control unit, for example.

Abstract: An automotive vehicle braking system and method for controlling the same. The system includes an electronic controller communicatively coupled to a vehicle braking system and a vehicle motion detection device. The braking system is configured to be automatically activated in response to detection of an object in a path of the vehicle. Once activated, the braking system is deactivated either by the driver or a pre-determined time period after detection that motion of the vehicle has stopped. Prior to deactivation of the vehicle braking system an HMI message is activated indicating imminent deactivation of the vehicle braking system.

Abstract: The present invention discloses a dual-vision driving safety warning device and a method thereof. The device of the present invention comprises an image capture unit, an image processing unit, a vehicle status sensing unit, a warning judgment logic, and at least one warning unit. The image capture unit includes at least two image capture devices installed in a user's vehicle and capturing the images of the front traffic environment. The image processing unit processes the images and uses the vehicle status signals detected by the vehicle status sensing unit to calculate the distance between the user's vehicle and a front vehicle in the image. The warning judgment logic sends out a control signal when the user's vehicle deviates from a driving lane or approaches a front vehicle too much. The warning unit receives the control signal and sends out a warning signal, such as a sound or a flash, to remind the driver.

Abstract: A vehicle control system includes an actuator capable of adjusting a behavior of a vehicle, a temperature detecting device configured to detect a temperature of a tire on a wheel of the vehicle, and a control device configured to control the actuator according to the temperature of the tire detected by the temperature detecting device so as to change a degree of suppressing a behavior change of the vehicle by the actuator. Therefore, the vehicle control system can suppress a variation in a driving feeling.

Abstract: Embodiments of the invention are directed toward a geared traction drive system configured to drive a wheel of a vehicle, comprising: a driveshaft for transmitting power to the wheel; an electric drive motor for driving the driveshaft, the electric drive motor configured to receive signals from a vehicle dynamic control system to command a required speed; a gear reduction component for reducing the speed of the motor by a predetermined factor to a lower speed suitable for driving the wheel; and a drive electronics component that works with the electric drive motor to drive the wheel to the speed commanded by the vehicle dynamic control system.

Abstract: A braking control system includes sensors for detecting pressure applied to a brake pedal. The system can also include a pressure sensor capable of detecting the hydraulic pressure of the braking system. The system can also include a position sensor for detecting a position of the brake pedal. The pressure applied to the brake pedal is compared to either the hydraulic pressure or the pedal position. If the resulting measurements are not correlated properly, braking countermeasures are applied. Braking countermeasures can include engine braking, regenerative braking, hydraulic assist, and brake pad assist.

Abstract: The vehicle described herein employs a mu logic module. The mu logic module monitors vehicle operating conditions, and based on those operating conditions determines a road surface mu in response to a wheel slip event. The road surface mu is then used to determine a drive force to minimize or control the wheel slip event. The mu logic module continually monitors and adjusts the drive force provided to at least one of the wheels to maximize the applied drive force, while stabilizing and controlling wheel slip events to ensure safe operation of a vehicle.

Abstract: A hybrid powertrain includes an engine, an electric machine, and a transmission. A method to control the powertrain includes monitoring operation of the powertrain, determining whether conditions necessary for growl to occur excluding motor torque and engine torque are present, and if the conditions are present controlling the powertrain based upon avoiding a powertrain operating region wherein the growl is enabled.

Abstract: A method and apparatus for controlling a vehicle involves determining if the vehicle is swaying and if the vehicle is swaying, reducing a torque of an engine of the vehicle and/or applying independent braking forces to each wheel of the vehicle. A vehicle for controlling vehicle sway includes an engine, a plurality of wheels, a braking system configured to apply independent braking forces to each wheel, and a controller configured to control the engine and the braking system. The controller is configured to determine a correlation coefficient in accordance with any phase shift occurring between a yaw acceleration signal and a lateral acceleration signal. The correlation coefficient is compared to a threshold value to determine whether the vehicle is swaying. If the vehicle is swaying, the controller causes a torque of the engine to be reduced and/or braking forces to be applied independently to each wheel.

Abstract: A traction control system comprises a detector configured to detect a monitored spin value corresponding to a spin amount of a drive wheel in a vehicle; a condition determiner configured to determine whether or not the monitored spin value detected by the detector meets a driving power suppressing condition; and a controller configured to execute a traction control for reducing a driving power of the drive wheel based on the determination; the condition determiner being configured to set the driving power suppressing condition variably based on at least one of a variable parameter relating to a rotation number difference which is variable according to a change rate of a rotation number difference between the drive wheel and a driven wheel, and a variable parameter relating to rotation of a drive system which is variable according to a rotation change rate of the drive system for driving the drive wheel.

Abstract: A method of controlling a traction control system (30) includes continuously adapting a steady state driven wheel speed to reference wheel speed ratio, so that said traction control system can avoid unnecessary actuations (e.g., demanding torque reduction). The continuous adaptation methodology provides traction control robustness to vehicles equipped with a spare tire, or a different final drive such as in the use of aftermarket parts. The method includes a dual rate adaptation that allows both fast adaptation and fine tuning capabilities of the ratio. The method includes comparing the instant driven wheel speed to reference wheel speed ratio to the filtered driven wheel speed to reference wheel speed ratio, to obtain a ratio difference. When the difference is above a threshold, the first filter constant is selected and the first constant is applied to an adaptation filter, resulting in a first filtered and adapted ratio. The traction control system is controlled with the adapted ratio.

Abstract: A communication system for a vehicle includes a vehicle speed sensor configured to emit a periodic function with a parameter correlated to the speed of the vehicle, an acceleration monitoring system, a braking system engagement detector to detect a braking status of the vehicle, an alerting device capable of signaling other drivers of a deceleration condition of the vehicle, and a control device. The acceleration monitoring system is configured to compute the acceleration of the vehicle from variations in the parameter of the periodic function of the vehicle speed sensor and to output a deceleration status of the vehicle. The control device is coupled to the acceleration monitoring system, the braking system engagement detector, and the alerting device, wherein the acceleration monitoring system sends signals to the control device and the control device operates the alerting device in a manner dependent on the deceleration status of the vehicle.

Abstract: A vehicle stop control device is provided. The device is configured to perform a stop control for stopping a vehicle by adjusting a braking force for wheels and includes a target deceleration setting unit which sets a target deceleration as a target for stopping the vehicle so as to have a smaller value as a vehicle body velocity comes closer to zero, a deceleration obtaining unit which obtains a vehicle body deceleration of the vehicle, a control unit which performs the stop control of setting the braking force to have a smaller value as a subtraction value obtained by subtracting the target deceleration from the vehicle body deceleration is greater, and causing the set braking force to be applied to the wheels; and a determining unit which determines that a road surface is an ascent road when the braking force set by the control unit is zero.

Abstract: An automotive vehicle may include one or more controllers, a braking system and an electric machine. The one or more controllers may be configured to determine whether the vehicle is about to roll over. The braking system may be configured to apply a braking torque for a time period, under the command of the one or more controllers, to a front traction wheel to cause the front traction wheel to skid or slide relative to a road if the vehicle is about to roll over. The electric machine may be configured to generate a propulsion torque, under the command of the one or more controllers, during the time period.

Abstract: A cooperative traction control system wherein individualized control over each wheel's longitudinal slip and/or lateral skidding is provided. The system uses a combination of an existing traction and stability module linked with a drive torque actuator capable of modulating the amount of drive torque at a given wheel on a specified axle. The system permits drive torque at the slipping and/or laterally skidding wheel to be controlled, either alone or in combination with brake actuation and throttle angle control, to reduce or control wheel slip and/or lateral skid and/or vehicle motion.

Abstract: A control system for a lawnmower vehicle having a plurality of electric motors may include at least one controller for controlling operation of the drive wheel electric motor in response to an operation amount of at least one operator. The controller may control operation of a driver for driving a mower-related electric motor to cause the mower-related electric motor to activate or stop.

Abstract: A method and system for varying an output of a driveforce unit based on load data. The present invention includes an automobile including a driveforce system. The driveforce system includes a driveforce unit for generating an output according to a driveforce map, a memory for storing the driveforce map, a load determination unit for determining a load data indicating a load on the automobile, a speed sensor for detecting speed data indicating a speed of the automobile and/or an acceleration of the automobile, an acceleration input device for detecting acceleration input data indicating a percent application of the acceleration input device, and a processor. The processor receives the acceleration input data, the speed data, and the load data, and adjusts a driveforce curve in the driveforce map to maintain a speed of the automobile, even when the load data indicates an increased or decreased load on the automobile.

Abstract: A method for enhancing stability of a three wheel vehicle having a pair of front wheels and a single rear wheel, each of the wheels having a tire with a tire grip threshold. The method including deploying an electronic stability system (ESS) on the vehicle, providing the ESS with input from various vehicle sensors related to the longitudinal and lateral acceleration of the vehicle, causing the ESS to determine whether (i) a precursory condition indicative of a wheel lift exists and (ii) the tire grip threshold of any of the tires has been exceeded; and when a precursory condition indicative of a wheel lift exists and the tire grip threshold of none of the tires has been exceeded, causing the ESS to reduce the longitudinal acceleration of the vehicle by a first amount less than that which would cause the tire grip threshold of any of the tires to be exceeded.

Abstract: A vehicle is provided comprising: a main body; a plurality of wheels coupled to the main body; a traction motor associated with the main body and coupled to at least one of the wheels for driving the one wheel; control apparatus coupled to the traction motor and generating a motor drive signal to the traction motor; a first sensor for generating a velocity signal indicative of a velocity of the driven wheel; and a further sensor for sensing an acceleration of the main body and generating a vehicle acceleration signal. The control apparatus determining a measured velocity of the driven wheel from the first sensor speed signal, calculating a velocity of the vehicle using the vehicle acceleration signal and comparing the measured velocity of the driven wheel to the calculated velocity of the vehicle to determine wheel slip status.

Abstract: Provided are a braking control system for a vehicle which is controlled in a priority order, and a method of the same. A braking control system for a vehicle equipped with an electronic brake at each wheel includes a first control unit controlling the operation of a first electronic brake mounted at a front-left wheel and a second electronic brake mounted at a front-right wheel in response to braking signals, and a second control unit controlling the operation of a third electronic brake mounted at a rear-left wheel and a fourth electronic brake mounted at a rear-right wheel in response to the braking signals. In this configuration, when a fail occurs in any one of the first and second control units, the other control unit selectively controls at least one or more of the first to fourth electronic brakes, in accordance with predetermined logic.

Abstract: A slip control apparatus includes a driving torque calculating means calculating driving torque, a driving torque applying means applying the calculated driving torque to driving wheels, and a slip restraining means restraining slippage at each driving wheel when the slippage occurs at each driving wheel, wherein when the slippage occurs at each driving wheel, the driving torque calculating means calculates demanded torque and adds consumed driving torque, which corresponds to the driving torque consumed for restraining the slippage at each driving wheel by the slip restraining means, to the calculated demanded torque to calculate the driving torque.

Abstract: A method of controlling at least one coupling in a powertrain of a motor vehicle includes the steps of: determining at least one slip value which represents an instantaneous slip between different axles of the motor vehicle or between different wheels of an axle; forming an absolute value of the slip value which corresponds to the amount of the slip value; summing the absolute value or a substitute value derived therefrom to a last-formed slip sum value to form an instantaneous slip sum value; comparing the instantaneous slip sum value with a slip sum threshold value: and generating a control signal for actuating the coupling if the instantaneous slip sum value reaches or exceeds the slip sum threshold value.

Abstract: Methods are provided for controlling a vehicle speed during a downhill travel. Based on the estimated grade of the downhill travel and further based on an input received from the operator, different combinations of an engine braking torque and a regenerative braking torque are used to maintain the vehicle speed during the downhill travel. A battery rate of charging is also adjusted based on the duration or distance of the downhill travel, as indicated by the operator input.

Abstract: Method and arrangement for setting a speed limit for vehicle travelling on a road includes monitoring conditions of the road, determining a speed limit for travel of vehicles on the road based on the monitored conditions, and transmitting the determined speed limit to the vehicles to thereby notify operators of the vehicles of the determined speed limit. Monitoring conditions of the road may entail monitoring weather conditions around the road, monitoring visibility for operators of the vehicles on the roads, monitoring traffic on the road, monitoring accidents on the road or emergency situations of vehicles on the road and/or monitoring the speed of vehicles travelling on the road and a distance between adjacent vehicles.

Abstract: The described system and method are implemented within a motor grader or other machine for grading of surfaces, wherein the machine includes a ground engaging element, as well as one or more blades for removing surface material. In this context, the described system and method prevent slippage of the ground engaging element against the underlying surface. In an embodiment, a torque limit is applied, wherein the torque limit corresponds to a torque that is less than that required for slippage under the current operating conditions, thus avoiding the problems caused by both overly aggressive and overly conservative cut depth strategies.

Abstract: A method for assessing slippage of wheels in a vehicle includes the steps of measuring, via a sensor, an initial value of vehicle speed, determining, via a processor, at least one of a minimum vehicle speed and a maximum vehicle speed, and determining, via the processor, wheel slip using the initial value and the at least one of the minimum vehicle speed and the maximum vehicle speed.

Abstract: According to one aspect, a vehicle control system. The control system includes a steering control coupled to at least one steerable wheel, the steering control having a first position, a second position and a plurality of positions therebetween. The control system also includes a steering sensor coupled to the steering control and configured to generate steering sensor signals based upon the position of the steering control. The control system also includes a control module coupled to the steering sensor, the control module configured to (i) record a first steering sensor signal value when the steering control is in the first position; (ii) record a second steering sensor signal value when the steering control is in the second position; and (iii) determine a current position of the steering control by comparing the first and second steering sensor signal values with a current steering sensor signal value.

Abstract: A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel in a manner compatible with Anti-skid control. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. Upon starting anti-skid control for either of the wheels during the execution of BFD control, an increment of the front wheel braking forces to be requested by BFD control is gradually decreased. Simultaneously, the holding of the rear braking force is released so as to compensate for the shortage of braking force on the front wheel. The gradual decrease of the braking force increment prevents a conflict of BFD and Anti-skid control.

Abstract: A method for making it possible to set the link between all the types of vehicles and roads with the rolling limits on the roadway is described. This setting can be established from the existing road data bases and from the characteristics of the known vehicles. This method is capable of determining the vehicle rolling limits. A device which can be fitted on any vehicle and capable of implementing the method according to the invention is also disclosed.

Abstract: A method of managing operation of a machine is described herein. The machine includes drive components that supply a propulsive force exerted by the machine on a traveled surface. The machine includes a programmed controller that controls power output by a motor to the drive components of the machine, in accordance with a slippage model, to actively manage excessive slippage at a physical interface between the machine and the traveled surface. The programmed controller determines a track force indicative of the propulsive force exerted by the machine on the traveled surface. The programmed controller further determines a modeled slippage based, at least in part, upon the track force and the slippage model. The machine conditionally causes a reduction of the power output by the motor based upon a comparison, by the programmed controller, between the modeled slippage and a slippage limit.

Abstract: A travel control device for a work vehicle includes: a hydraulic pump; a plurality of hydraulic motors connected to the hydraulic pump in parallel through a closed-circuit connection, that drive different wheels with pressure oil delivered from the hydraulic pump; a slip detection device that detects a slip occurring at each of the wheels; and a flow control device that reduces, upon detection of a slip occurring at any of the wheels by the slip detection device, a quantity of pressure oil supplied to a hydraulic motor for driving the wheel at which the slip has been detected, among the plurality of hydraulic motors.

Abstract: Vehicle control system and method in which restrictions on travel of the vehicle are determined based on an indication of the visibility of a driver and information about objects moving in a direction opposite to the direction of travel of the vehicle are considered. The travel restrictions include preventing a passing maneuver on a two-lane road when an oncoming vehicle precludes safely initiating or completing an already-initiated passing maneuver. A warning system is provided to warn a driver about the travel restrictions so that the driver will, hopefully, not attempt an unsafe maneuver.

Abstract: A system and method of continuously updating a steering wheel angle offset value to adapt to changing road conditions. A vehicle control system receives a plurality of vehicle parameter values each from a different vehicle sensor. The system then calculates a plurality of observed steering angle values, each using a different calculation method based on one or more of the plurality of vehicle parameter values. The plurality of observed steering angle values are then used to calculate a vehicle steering angle. A steering wheel angle offset value is then calculated based on the steering wheel angle and the calculated vehicle steering angle. The steering wheel angle offset value and the steering wheel angle are used to control the vehicle's steering system.

Abstract: One disclosed embodiment relates to a propulsion system for a machine. The propulsion system may include a prime mover operatively connected through a continuously variable transmission to a propulsion device. The propulsion system may also include propulsion-system controls that control an operating parameter of the continuously variable transmission, which may include adjusting the operating parameter based on operator input. Controlling the operating parameter may also include determining an adjustment limit for the operating parameter based on one or more operating conditions and applying the adjustment limit to the operating parameter to modify at least one of acceleration and jerk of the machine based on the one or more operating conditions.

Abstract: In a method for detecting wheel slip at at least one wheel which is driven by an engine, the drive torque acting upon the wheel is varied, and the reaction of the wheel to the change in the drive torque is measured and evaluated.

Abstract: A method for identifying a driving resistance of a motor vehicle includes the steps of recording values of control and/or state variables of the vehicle during a driving state of the vehicle when a control route is covered, adapting parameters of a vehicle model and/or a model of the area surrounding the vehicle on the basis of the values of the recorded control and state variables, identifying the driving resistance on the basis of the adapted vehicle model and/or the surrounding area model, wherein the parameters of the vehicle model and/or the surrounding area model are adapted on the basis of a distinction between driving states, wherein these driving states include a driving state of a closed drive train with a positive driver demand torque, a driving state of a closed drive train without a positive driver demand torque, and/or and a driving state with an open drive train.

Abstract: A riding lawnmower includes left and right wheels, at least one caster wheel, a lawnmower blade or reel, and a control section. The left and right wheels are independently driven by electric rotary machines to travel. The lawnmower blade or reel is driven for mowing. The control section, in response to turn instruction input by a turn operator, controls the left and right wheels according to preset standard setting conditions, or according to deceleration setting conditions which differ from the standard setting conditions, under which at least one of a vehicle movement speed and vehicle turning speed is decelerated more than under standard setting conditions. The riding lawnmower includes a section designating either standard setting conditions or deceleration setting conditions. In a riding lawnmower, left and right wheels are caused to turn around a turn center position corresponding to a turn instruction according to designated setting conditions.

Abstract: A power steering device is mounted on a vehicle and includes a torque applying unit and an applied friction torque changing unit. The torque applying unit sets an applied friction torque applied to a steering wheel based on a real steering angle and a target steering angle, and performs a control of applying the applied friction torque to the steering wheel. The applied friction torque changing unit changes the applied friction torque based on a load condition of the vehicle.

Abstract: An acceleration-based method and device for the safety monitoring of a drive is provided. In the method a setpoint torque is calculated in a safety function as a function of the position of the accelerator pedal. An expected vehicle acceleration is determined, as a function of the setpoint torque, in the safety function. An actual vehicle acceleration is determined, preferably by an acceleration sensor. A fault situation may be detected by comparing the actual vehicle acceleration and the expected vehicle acceleration. A device, preferably included in the vehicle electronics, is configured to implement the acceleration-based method.

Abstract: A vehicle includes a slip detection section arranged to detect a slip of a driving wheel based on the rotation speed of the driving wheel and the vehicle speed, and an engine control section arranged and programmed to perform control to decrease the output of an engine when the slip of the driving wheel is detected by the slip detection section. When the automatic clutch is in a half clutch state and the slip of the driving wheel is detected, the engine control section executes neither ignition retarding control on an ignition device nor a fuel injection amount decreasing control on a fuel injection valve, and executes control to decrease an opening of a throttle valve.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel in a combustion chamber of the engine. A main injection and a pilot injection are performed through the at least one fuel injection valve, the pilot injection being performed before the main injection. A demand output of the engine is temporarily reduced upon a request for reducing an output of the engine. The output of the engine is reduced when the demand output is reduced. A control of the pilot injection corresponding to a state where the demand output is not reduced is performed when the demand output is reduced.

Abstract: In apparatus for controlling operation of a four-wheel drive vehicle having a prime mover (engine), drive wheels driven by the prime mover and free wheels, a VC (viscous coupling; torque transferring device) installed between the drive wheels and free wheels to transfer torque generated in response to a difference between inputted and outputted rotation thereof, output of the prime mover is decreased based on a desired rotational speed of the drive wheels driven by the prime mover when calculated difference between inputted and outputted rotation of the VC is equal to or greater than a predetermined value, thereby enabling to control the driving force effectively so as to achieve required vehicle driving performance.

Abstract: A method for ascertaining a rotational speed parameter for determining a setpoint torque for driving a drivetrain. The drivetrain comprises a first and at least one second drive assembly for driving a hybrid vehicle. The first drive assembly can be coupled to the drivetrain by means of a clutch. The second drive assembly is mechanically coupled to the drivetrain. When the hybrid vehicle is being driven by means of at least the first drive assembly, the rotational speed parameter corresponds to the value of a shaft rotational speed. When the hybrid vehicle is being driven only by means of the second drive assembly, the rotational speed parameter corresponds to the value of a determined rotational speed.

Abstract: In order to cause a computer to execute integral calculation of an integrand, to thereby calculate a value of a second variable used at each calculation time point, the integrand being defined by: a first variable to which a value is given at all calculation time points; and the second variable to which only an initial value is given, the following processing is executed. First, a partial derivative which is obtained by partially differentiating the integrand for the second variable is read out from a storage device. At each calculation time point, the initial value or a value of the second variable calculated at a last calculation time point and a value of the first variable given at a current calculation time point are substituted into each of the integrand and the partial derivative, to thereby calculate a value of the integrand and a value of the partial derivative at the current calculation time point.

Abstract: A turf maintenance vehicle all-wheel drive traction control system includes a primary wheel propelling the vehicle. A first motor rotates the primary wheel. A traction control system has a first portion communicating with the first motor to monitor either a first motor current demand or a rotational speed of the primary wheel or the first motor and generates a traction control value. A secondary wheel rotated by a second motor steers the vehicle in a vehicle non-slip condition. A traction control system second portion determines a secondary wheel steering angle value. A speed threshold limit stored in the traction control system compared to the traction control value generates a slippage occurrence message indicative of a primary wheel traction loss event. A second motor drive signal created by comparing the steering angle value and the slippage occurrence message energizes the second motor during the traction loss event.