Nissan Motor Company Limited

Yoshiyuki Etoh

Hiroshi Inoue

Isao Yamamoto

Hiroyuki Nomura

Kinichiro Nakano

Kazuyuki Mori

Kiyoshi Yoshida

Jian Chen

Hiroshi Tanaka

Kouichi Suzuki

Sadao Takase

Yasuhisa Takeuchi

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which a target opening angle of an engine throttle valve through which the vehicle can maintain a set cruise speed is derived in accordance with a prepared non-linear characteristic table and an opening angle of the throttle valve is controlled so that a detected vehicle speed coincides with the set cruise speed and a detected opening angle of the throttle valve coincides with the target opening angle. In addition, when the detected vehicle speed and detected opening angle are substantially constant for a predetermined time due to the vehicle being run on a flat road, average values of both detected vehicle speed and detected opening angle are derived and the above-described non-linear characteristic is corrected using both average values.

System and method for automatically controlling vehicle speed to desired

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which in addition to a control unit and a throttle actuator through which an opening angle of an engine throttle valve is adjusted so that the vehicle speed detected by a vehicle speed sensor coincides with a target cruise speed set by a vehicle driver through a set switch, a vehicle speed determining circuit is provided for determining whether the vehicle speed detected by the vehicle speed sensor exceeds a lowest speed limit above which the cruse control by the control unit and throttle actuator becomes effective. When the vehicle speed is below the lowest speed limit, the power supply to the throttle actuator is interrupted so that the cruise control by means of the throttle actuator is cancelled.

System and method for automatically controlling a vehicle speed to a

A system and method for automatically controlling a vehicle speed to a desired cruise speed includes an inhibit switch connected in parallel to a line between a power supply and a main self hold power supply switch (self-hold type) of an automatic cruise controlling system. When the vehicle speed is below a predetermined value, the inhibit switch is open so that the automatic cruise speed controlling system cannot receive power via the main, switch. Thus, wasteful comsumption of power is reduced.

System and method for automatically controlling vehicle speed to a

A cruise control system for an automotive vehicle with a manual or automatic transmission, includes an inhibition circuit. The inhibiting circuit blocks communication between a power supply and an actuator and/or a controller when the manual transmission is set in a predetermined gear or when the automatic transmission is set in a driving range other than the drive range, so as to inhibit the controller from operating in the cruise control mode. When the vehicle is provided with an automatic transmission which is selectively set in first, second, third or fourth gear while the shift lever is set in the drive range position, the cruise control system includes a first inhibiting circuit which blocks the communication when the shift lever is set in a position other than the drive range position, and a second inhibiting circuit which blocks the communication when the automatic transmission is set in either the first or second range while the shift lever is set in the drive range position.

Cruise control system for automotive vehicle

A system for automatically controlling vehicle speed calculates the relative speed between the subject vehicle and another preceding vehicle on the basis of the intervehicle distance detected by an intervehicle distance detector. One of a number of relative speed values derived with reference to different sampling periods is selected according to the magnitude of one of the relative speed values so that a highly accurate and fast responsive system for controlling the vehicle speed can be achieved on the basis of the vehicle speed, intervehicle distance, and selected relative speed.

System and method for automatically controlling vehicle speed so as to

A System and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which a control unit determines whether a control mode is a steady state mode in which the vehicle cruises at a set target vehicle speed or a transient state in which the target vehicle speed is transiently changed on the basis of input data of the actual vehicle speed, set target vehicle speed, an actual opening angle of an engine throttle valve, and a target opening angle of an engine throttle valve determined on the basis of a running resistance of the vehicle. In the steady state mode, the control unit controls a throttle actuator so that the target opening angle of the throttle valve coincides with the actual vehicle speed and actual vehicle speed is matched with the target vehicle speed. In a transient mode in which the vehicle speed is set in an acceleration or in a deceleration, a power supply signal supplied to the throttle actuator is variably controlled and the variable control is continued until the actual opening angle is matched with the target opening angle of the throttle valve. Therefore, a smooth switching between the steady state mode and transient state mode can be achieved.

System and method for automatically controlling vehicle speed to cruise

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which a vehicle speed sensor which output an analog quantity corresponding to a current vehicle speed is provided, a vehicle speed determining circuit which derives the current vehicle speed on the basis of the analog quantity derived from the vehicle speed sensor and determines whether the derived current vehicle speed is below a predetermined speed above which the cruise speed control run is appropriate is furthermore provided independently of a control unit of the system. When the vehicle speed determining circuit outputs a determination signal indicating that the current vehicle speed is below the predetermined speed and the control unit outputs a predetermined control command signal, a power supply line connected to a throttle valve actuator is, at first, interrupted. Then, the power supply to the control unit is interrupted.

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which whether a microcomputer of a control unit is enabled to perform a cruise speed control is determined on the basis of a plurality of determining factors and a power supply of a throttle actuator for actuating an engine throttle valve so as to adjust an opening angle of the throttle valve is enabled only when all of the determining factors satisfy a condition of enabling the cruise speed control via the actuator and is disabled when at least one of the determining factors does not satisfy the condition.

A system and method for automatically controlling a vehicle speed to a desired cruising speed are disclosed in which such a control is inhibited that the opening angle is adjusted toward a prohibiting range in which an engine output torque becomes substantially constant even if the opening angle of the throttle valve is increased more than necessary. At this time, the opening angle is adjusted to a predetermined limit angle (for example, 40 degrees) and a transmission gear position is controlled depending on a difference between an instantaneous vehicle speed and a target vehicle speed. Therefore, unnecessary opening of the throttle valve exceeding the predetermined limit beyond which little increase in the engine output torque occurs can be avoided. In addition, the throttle valve can immediately be controlled from the predetermined limit to a target opening angle at which the vehicle speed can be maintained at the target vehicle speed.

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which when a vehicular running resistance is derived on the basis of an engine torque and change rate of the vehicle speed with time, the engine torque being derived on the basis of an engine revolutional speed and engine load, a predetermined factor determining the running resistance is derived on the basis of the running resistance. In addition, an absolute value of a difference of the predetermined factor from a previous predetermined factor derived one predetermined calculation period before is compared with a predetermined threshold value, a zero engine driving force command is outputted to an actuator of an engine driving force adjustng mechanism so that the engine driving force adjusting mechanism is actuated to zero the engine driving force to recover gripping forces of drive wheels when the absolute value of the difference exceeds the predetermined threshold value.

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which an opening angle of a first throttle valve is adjusted so that the vehicle speed coincides with a target vehicle speed at which the vehicle cruises. The cruise control for the vehicle speed through the first throttle valve is inhibited when an occurrence of a slip on a drive wheel is detected and a traction control by means of a traction controlling system such that a driving force of the vehicle is reduced through a second throttle valve disposed in series with the first throttle valve in an engine intake air passage is executed so that an effective traction control can be achieved without interference of both systems when the vehicle enters on a road surface having a very low friction coefficient.

System for automatically controlling vehicle speed to desired cruise

A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which whether after any one of command and release signals is outputted from the corresponding set/cruise, acceleration, resume, brake, clutch, and cancel switches, a control unit outputs a corresponding receipt signal via a corresponding output port is determined, whether the contents of the control command signals presently outputting through the respective control valves are equal to inverted levels at the respective control valve is determined, and a power supply to control valves for adjusting an operating variable of an engine driving force adjusting mechanism and the control unit is interrupted when at least one of the results of determinations indicates a negative result. In addition, when the control unit outputs the control command signals to the control valves to increase the vehicle speed, a subroutine of monitoring a cruise speed control enable state from the vehicle speed, command switches, release switches, and flag indicating the cruise control state in the control unit is executed.

A system and method for automatically controlling a vehicle speed to a desired cruising speed applicable to vehicles in which a basic manipulated variable corresponding, for instance, to an operation time of either of acceleration or deceleration valve in an actuator for actuating an engine throttle valve of a vehicle in which the system is mounted toward the acceleration or deceleration direction which is derived on the basis of the vehicle speed and target cruising speed so that the vehicle speed coincides with the desired target cruising speed is corrected according to a transfer function of a response to the opening angle of the throttle valve to the manipulated variable. The response of the throttle valve to a change in the manipulated variable is measured and the transfer function is computed on the basis of the measured response to compensate for vehicle variations and aging effects.

A system and method for automatically running a vehicle at a desired cruising speed, in which a running resistance of the vehicle is always derived, a target opening angle of a throttle valve of a vehicular engine which can run the vehicle at a desired constant acceleration and/or at the desired cruise running speed is derived under the derived running resistance, and the opening angle of the throttle valve is controlled in a feedforward control mode so as to coincide with the target opening angle. The automatic cruise running system and method can achieve no variation of vehicle speed when the vehicle runs on a rugged road.

System and method for automatically running a vehicle at a desired

A system and method for automatically running a vehicle at a desired cruising speed in which in order to properly control an opening angle of a throttle valve of a vehicular engine, the opening angle of the throttle valve is feedforward controlled. In the feedforward control, a wheel force of the vehicle is derived by storing an instantaneous angular displacement of the throttle valve for each period of controlling the angular displacement of the throttle valve, weighting transient characteristics of a transmission torque in a power train of the vehicle including dead times and first order lag to the stored instantaneous angular displacement of the throttle valve to derive each wheel force for the period of controlling the angular displacement of the throttle valve, and averaging each wheel force for each period of deriving a change rate of the vehicle speed to derive the wheel force. The wheel force is used to derive a running resistance of the vehicle based on deriving a target angular displacement of the throttle valve to maintain the vehicle speed at the cruising speed.

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Kanagawa, Japan

Yoshiyuki Etoh