Abstract: A mobile robot configured to move on a ground. The mobile robot including a contact angle estimation unit estimating contact angles between wheels of the mobile robot and the ground and uncertainties associated with the contact angles, a traction force estimation unit estimating traction forces applied to the wheels and traction force uncertainties, a normal force estimation unit estimating normal forces applied to the wheels and normal force uncertainties, a friction coefficient estimation unit estimating friction coefficients between the wheels and the ground, a friction coefficient uncertainty estimation unit estimating friction coefficient uncertainties, and a controller determining the maximum friction coefficient from among the friction coefficients such that the maximum friction coefficient has an uncertainty less than a threshold and at a point of time when the torque applied to each of the wheels changes from an increasing state to a decreasing state, among the estimated friction coefficients.

Abstract: A slip suppression control system for a vehicle includes a monitored value detecting device for detecting a monitored value corresponding to a difference between a rotational speed of a front wheel and a rotational speed of a rear wheel of the vehicle, a threshold determiner unit configured to determine a relationship between the monitored value detected by the monitored value detecting device and a threshold; and a controller configured to initiate traction control for reducing a driving power of a drive wheel when the threshold determiner unit determines that the monitored value exceeds a predetermined start threshold, wherein the threshold determiner unit is configured to count a return time which lapses from when the monitored value exceeds the start threshold until the monitored value becomes smaller than second threshold; and wherein the controller is configured to determine whether or not to terminate the traction control based on the return time.

Abstract: An active vibration insulator includes an electromagnetic actuator, a controller, and a bad-roads processor. The electromagnetic actuator generates vibrating forces depending on electric-current supplies. The controller carries out vibrating-forces generation control. In the vibrating-forces generation control, the electric-current supplies are made variable so as to actively inhibit vibrations generated by an on-vehicle vibration generating source of a vehicle from transmitting to a specific part of the vehicle based on cyclic pulsating signals output from the on-vehicle vibration generating source. Thus, the controller lets the electromagnetic actuator generate the vibrating forces. The bad-roads processor stops the vibrating-forces generation control effected by the controller when the vehicle travels on bad roads.

Abstract: An apparatus for calculating an initial correction coefficient for correcting rotational angular velocities obtained from outputs of rotational angular velocity detecting means. The apparatus includes a judged value calculating means which calculates a judged value on the basis of the rotational angular velocities; an identifying means which identifies whether the vehicle is performing turning movements at high velocity, straight-ahead running or turning movements at mid/low velocity; and an initial correction coefficient calculating means which obtains an initial correction coefficient when it has been identified by the identifying means that the vehicle is performing straight-ahead running or turning movements at mid/low velocity. It is possible to obtain accurate correction coefficients so that it is possible to accurately detect, for instance, a decrease in tire air-pressure and thus to maintain safe running.

Abstract: An antiskid control system for a four-wheel-drive vehicle is arranged to calculate a difference between an average of wheel accelerations of front wheels and an average of wheel acceleration of rear wheels. When the difference is greater than or equal to the vibration determination threshold, the antiskid control system determines that a driveline vibration is generated and executes a control for converging the driveline vibration.

Abstract: An antiskid control system for a four-wheel-drive vehicle is arranged to calculate a difference between an average of wheel accelerations of front wheels and an average of wheel acceleration of rear wheels. When the difference is greater than or equal to the vibration determination threshold, the antiskid control system determines that a driveline vibration is generated and executes a control for converging the driveline vibration.

Abstract: For determining a reference speed which is approximated to the actual vehicle speed, at least two wheel sensors are provided for each wheel speed to be measured. All existing wheel sensors are analyzed, and only one is selected and used for determining the reference speed as a function of the actual driving condition and of at least one defined speed criterion. At least one sensor is always available for controlling each wheel, even if one sensor is faulty.

Abstract: An improved method of operation for a motor vehicle automatic transmission determines a vehicle speed for purposes of selecting a desired transmission gear at least in part based on the wheel speeds of the vehicle. If the vehicle is being operated in a two-wheel drive mode, the vehicle speed is determined based on an average of the speeds of the un-driven wheels; if the vehicle is being operated in a four-wheel drive mode, the vehicle speed is determined based on the lowest of the four wheel speeds. Optionally, the wheel speeds are only used to determine vehicle speed if the Reverse range of the transmission has been engaged within a specified time interval, and otherwise the vehicle speed is determined based on an output speed of the transmission.

Abstract: A braking control apparatus for vehicles is provided with a braking control for performing such control that when deceleration d determined by a deceleration determining device is not less than a predetermined value f(v) according to vehicle speed v determined by a vehicle speed determining device, a braking force exerted on a rear wheel is limited as compared with a braking force exerted on a front wheel. This predetermined value f(v) is set so as to become smaller with increase in the vehicle speed v.

Abstract: Disclosed is a method for identifying a critical braking operation of a two-track vehicle during cornering, which features the steps of detecting the running behaviour of a left-hand side wheel and of a right-hand side wheel, of comparing the running behaviour and/or of evaluating the time variation of at least one left-hand side wheel or right-hand side wheel, and of identifying a critical braking operation on the basis of the result of the comparison and/or of the result of the evaluation. As a reaction, there may ensue the reduction of the braking pressure of a wheel on the inside of the corner in response to identification.

Abstract: There is provided an automotive brake control system capable of executing ABS control (skid control), in which when an abnormality such as superimposition of noise on the output of a wheel speed sensor occurs, a pseudo vehicle body speed is generated by wheel-speed sensor signal excluding an abnormal wheel-speed sensor signal. The automotive brake control system includes an abnormality judgment section which determines whether an abnormal wheel-speed sensor signal is included in the wheel-speed sensor signals. The abnormality judgment section cooperates with a pseudo vehicle body speed generating section for generating a pseudo vehicle body speed based on the wheel-speed sensor signals except the abnormal wheel-speed sensor signal when the abnormality judgment section determines that the abnormal wheel-speed signal is present.

Abstract: A brake control system is constructed to obtain a pseudo body velocity in accordance with outputs of wheel-velocity sensors, to control said brake unit in accordance with a difference between each wheel velocity and the pseudo body velocity to reduce the pressures within wheel cylinders for ABS control, to determine that one of the outputs of the wheel-velocity sensors is abnormal when a pressure-reduction time measured during ABS control exceeds a predetermined value, and to form the pseudo body velocity, if an anomaly of one of the outputs of the wheel-velocity sensors is determined, in accordance with the outputs of the wheel-velocity sensors excluding the abnormal wheel-velocity sensor.

Abstract: In order to obtain the vehicle speed of an ordinary automobile operating with a pair of drive wheels and a pair of driven wheels, so as to provide the base of a due slipless rotation speed of the respective wheels for use in an ABS control, the rotation speed of each of the pairs of drive and driven wheels are detected. Then the data signals generated by the detection are low pass filtered and checked to determine if any of the rotation speeds detected with the driven wheels is larger than the largest of the filtered rotation speeds. Then the vehicle speed is determined from the filtered rotation speeds, excluding that or those of the driven wheel or wheels whose detected rotation speed is larger than the largest of the filtered rotation speeds.

Abstract: A system including a method for improving the driving performance of a vehicle when braking during cornering comprises the following steps: detecting cornering and the direction of cornering, determining the rolling characteristics of individual wheels, if necessary, influencing the braking pressure of the brake on one wheel or on several wheels according to the rolling characteristics of these wheels, checking the driving condition of the vehicle with respect to whether instability prevails, and modifying the braking pressure of at least one brake of a wheel when an instability is detected during a cornering maneuver extending for a time period that reaches a threshold time period.

Abstract: Anti-lock braking system for an automobile is disclosed. It includes a brake unit that can control brake pressures within wheel cylinders of each road wheels of the automobile separately. In an anti-lock control mode, a control unit is operative to determine a controlled wheel speed for a road wheel to be controlled. The control unit determines a slip of the road wheel based on the determined controlled wheel speed and activates the brake unit in a direction to decrease the determined slip. In determining the controlled wheel speed, the control unit is operative to select a higher one of actual wheel speeds of front and rear road wheels on the opposite side to the side where the road wheel to be controlled exists. Then, the control unit is operative to use, as the controlled wheel speed, a lower one of an actual wheel speed of the road wheel to be controlled and the selected higher one wheel speed.

Abstract: A method and an apparatus for determining a variable describing the speed of a vehicle are provided. In this method, for at least two wheels, the speeds of those wheels are determined, and the variable describing the speed of the vehicle is determined at least as a function of the speed of a selected wheel. For this, an operating state of the vehicle is determined based on the speeds of at the least two wheels, the selected wheel being determined at least as a function of that operating state. In addition, plausibility queries for determining the selected wheel are performed for some of the determined operating states of the vehicle, as a function of the particular operating state of the vehicle that is determined.

Abstract: An antilock brake control system in a vehicle is designed to retard the pressure increasing timing in one of front and rear wheel braking liquid pressure regulating devices which corresponds to a wheel having a smaller load share, until the wheel speed of such wheel is started to be reduced while following an actual vehicle speed after being restored to near the actual vehicle speed, when both of front and rear wheels are in antilock brake-controlled state.

Abstract: An antiskid brake controller, which can secure safety by avoiding a cascade caused when a braking pressure is reduced in a four-wheel-drive vehicle, includes wheel speed sensors braking force adjuster for adjusting a braking pressure and an ECU for calculating the control amount of a breaking force adjuster so as to prevent the locking tendency of each of the wheels based on a wheel speed Vw. The ECU includes means for the wheel deceleration calculator Gw corresponding to the locking tendency of each of the wheels, a basic vehicle calculator speed, a slip amount calculator SL based on the wheel speed Vw and the basic vehicle speed, cascade determination device for determining the occurrence of the cascade state when an unstable state occurs such that the slip amounts of three wheels are larger than a predetermined value and control amount corrector for changing the control amount of the braking pressure in an increasing pressure reduction amount when the occurrence of the cascade is determined.

Abstract: An anti-lock brake control system capable of performing optimal control of braking hydraulic pressure in a motor vehicle having four wheels while preventing brake application from being released by setting an optimal pseudo vehicle speed by effectively making use of the wheel speeds of four wheels in arithmetic determination of a pseudo vehicle speed on a wheel basis. The anti-lock brake control system includes wheel speed detector (101a to 101d) for detecting rotation speeds of four wheels, respectively, reference wheel speed arithmetic calculators (102a to 102d) for setting limits on the wheel speed of the wheels in consideration of positional relations of the wheels relative to one wheel of concern to thereby determine a reference wheel speed, and pseudo vehicle speed arithmetic calculators (103a to 103d) for arithmetically determining the pseudo vehicle speed on the basis of the reference wheel speed.

Abstract: An anti-lock control method whereby a control period of pressurization/pressure-reduction during anti-lock control is maintained constant. In the anti-lock control method, a control period T(n) from a high peak of a body velocity to a next high peak is measured, a difference between a target control period time (Tset) and the control period time T(n) is obtained when the control period time is shorter than the target control period time (Tset), the difference is added to a current pressurization start delay time Twait(n-1) to obtain a next pressurization start delay time Twait(n), and a next pressurization start time is delayed by the obtained pressurization start delay time.

Abstract: The present invention describes a process for a vehicle including an electronic control system, which processes input signals representative of the rotational behavior of the individual wheels, and wherein the differences of the tire tread circumferences of the individual wheels are determined by way of short-time and long-time correction factors. The long-time correction factors LZ.sub.n. are determined from the differences D.sub.R1 between the short-time correction factors KZ.sub.R1 and the long-time correction factors LZ.sub.R1 of the respective wheel by averaging LM.sub.r1 the differences during a predetermined time interval and by evaluating and weighting the average value. For the quick identification of an emergency wheel, every time the vehicle engine is started, the long-time factor LZ.sub.R1 is equalled once to the short-time factor KZ.sub.

Abstract: A method is provided to correct the wheel speed for a vehicle equipped with a mini tire as the spare tire plus a nonvolatile memory device. The presence or absence of a mounted mini tire is detected while the vehicle is moving, and if a mini tire is mounted, the mounting information is stored in the nonvolatile memory. If an antilock control is triggered after the vehicle is restarted and in motion, a correction is made for the mini tire using the mounting information stored in the nonvolatile memory.

Abstract: The present invention is directed to a vehicle motion control system for maintaining vehicle stability by controlling the braking force applied to each wheel of a vehicle. The braking force applied to each wheel is controlled on the basis of outputs of the wheel speed sensors and the vehicle speed estimation unit. A limit value is calculated to a difference between a first estimated vehicle speed calculated for a second wheel located on the right side of the vehicle and a left estimated vehicle speed calculated for a left wheel located on the left side of the vehicle. The calculation of one of the first and second estimated vehicle speeds is limited in response to the limit value, so as to keep the estimated vehicle speed calculated for one of the right and left wheels rotating at a relatively low speed to be greater than a value subtracting the limit value from the second estimated vehicle speed provided for the other one of the right and left wheels rotating at a relatively high speed.

Abstract: A circuit arrangement for conditioning and evaluating the signals emanating from wheel sensors in a first stage determines the sensor(s) supplying the highest useful signal at very low wheel speeds. The signal from the most sensitive sensor is delivered when the wheel speed is below the predetermined speed threshold. Above the speed threshold, however, the signal from a sensor arranged on a driven vehicle wheel is used as the vehicle speed signal. The circuit is especially suitable for anti-lock and traction slip control systems which supply speed signals which can also be evaluated for other vehicle control or regulating systems.

Abstract: In an anti-lock brake control system for a vehicle, first presumed vehicle speeds are calculated in first vehicle speed calculating devices for every wheel based on wheel speeds detected by wheel speed detecting sections. A second presumed vehicle speed is calculated in a second vehicle speed calculating device based on the value of a lower one of the first presumed vehicle speeds calculated in the first vehicle speed calculating devices corresponding to the left and right rear wheels. A higher one of the first presumed vehicle speeds calculated in each of the first vehicle speed calculating devices and the second presumed vehicle speed calculated in the second vehicle speed calculating device is selected as a presumed vehicle speed corresponding to the wheel in a high-select device. The operations of actuators are controlled based on results of calculation of slip rates of wheels based on presumed vehicle speeds and wheel speeds for every wheel.

Abstract: A method of an accurate detection of a spinning vehicle wheel. Observed wheel speeds are derived by measuring the speed of each wheel and the slowest speed is set as the slowest observed wheel speed. A maximum probable wheel speed is derived by multiplying the slowest observed wheel speed by the ratio of the maximum wheel speed to the slowest wheel speed for a given minimum turning radius. The maximum probable wheel speed is compared with an observed wheel speed and if the observed wheel speed is greater, the wheel is deemed to be spinning.

Abstract: An anti-locking control system is described in which the by electrical interference in the range of the mains frequency of conventional power supplies are detected and eliminated. To that end, in the range of critical speeds, a new reference vehicle speed is formed from the ascertained vehicle speed only if the time intervals between the arriving signal edges of the various rpm sensors are not in the range of the mains frequency.

Abstract: In order to avoid faults as a result of different diameters of tires, under prescribed conditions a correction of one wheel speed with respect to the other on each side of the vehicle is performed. The conditions are based on a comparison of the throttle valve angle to the zero torque angle, and a comparison of the speed of the driven wheel to the speed of the non-driven wheel.

Abstract: A technique to indicate a different-diameter wheel such as a temporary tire and to accurately correct the wheel speed of the different-diameter wheel is determined. Wheel speeds of a pair of left and right driven wheels are detected by wheel speed sensors and wheel speeds of a pair of left and right follower wheels are detected by wheel speed sensors. Yaw rates are calculated from the wheel speeds of the left and right wheels, and yaw rates are calculated from the wheel speeds of the wheels located diagonally. Which wheel of the four wheels is a different-diameter wheel is determined based on the magnitudes of the four yaw rates and the wheel speed of the different-diameter wheel is corrected based on a ratio in wheel speed between the different-diameter wheel and the other wheels.

Abstract: To prevent a great variation of a detected wheel velocity for a period of time after a front wheel sensor or a rear wheel sensor for detection of a wheel velocity actually fails until a microcomputer detects the failure, it is determined whether or not an output pulse period of a front wheel sensor is equal to or shorter than a predetermined period. When the output pulse period exceeds the predetermined period, it is determined that there is the possibility that the front wheel sensor may be in failure, thus a front wheel velocity for a predetermined number of control cycles before (a front wheel velocity before the failure) is adopted as a front wheel velocity of the present control cycle. Also, a rear wheel velocity is calculated in a similar manner. For a time after a failure actually occurs until the failure is detected by a microcomputer, driving force control is not started even if other starting conditions for driving force control are satisfied.

Abstract: An apparatus for detecting wheel speed in a motor vehicle. The apparatus includes first, second, and third sensors for outputting pulse signals in response to rotations of rotary shafts of front left and right wheels and a drive shaft, respectively, and a rotational angular velocity calculating member for calculating first, second, and third rotational angular velocities of the first and second rotary shafts and the drive shaft from the pulse signals, respectively.

Abstract: An antilock brake control method for a four-wheel drive vehicle including calculating an estimated vehicle speed on the basis of a wheel speed of a wheel and a value obtained by adding an offset value to an output from a longitudinal acceleration/deceleration sensor for detecting a longitudinal acceleration or deceleration of the vehicle. When it is detected that all of the four wheels are in their spinning state, the addition of the offset value to the output from the longitudinal acceleration/deceleration sensor is stopped, and the estimated vehicle speed is calculated on the basis of the wheel speed and the output from the longitudinal acceleration/deceleration sensor.

Abstract: In order to avoid faults as a result of different diameters of tires, under prescribed conditions a correction of one wheel speed with respect to the other on each side of the vehicle is performed. The conditions are based on a comparison of the throttle valve angle to the zero torque angle, and a comparison of the speed of the driven wheel to the speed of the non-driven wheel.

Abstract: A brake pressure control apparatus for regulating a brake pressure for braking a wheel of a motor vehicle, including a device for obtaining a rotating speed of the wheel, a pressure regulator for regulating the brake pressure, on the basis of the rotary speed of the wheel, a running speed of the vehicle and an optimum slip amount of the wheel, a device for estimating a future speed of the wheel, on the basis of values of the wheel speed which have been obtained by the wheel speed obtaining device, and a device for reflecting the future speed of the wheel on the determination of a point of time at which the wheel brake pressure is regulated by the pressure regulator.