Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/02—Conjoint control of vehicle sub-units of different type or different function including control of driveline clutches
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/04—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units
  • B60W10/06—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of combustion engines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/18—Conjoint control of vehicle sub-units of different type or different function including control of braking systems
  • B60W10/184—Conjoint control of vehicle sub-units of different type or different function including control of braking systems with wheel brakes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
  • B60W30/18—Propelling the vehicle
  • B60W30/18009—Propelling the vehicle related to particular drive situations
  • B60W30/18027—Drive off, accelerating from standstill
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
  • B60W30/18—Propelling the vehicle
  • B60W30/18009—Propelling the vehicle related to particular drive situations
  • B60W30/18063—Creeping
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
  • B60W30/18—Propelling the vehicle
  • B60W30/18172—Preventing, or responsive to skidding of wheels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2520/00—Input parameters relating to overall vehicle dynamics
  • B60W2520/26—Wheel slip
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2520/00—Input parameters relating to overall vehicle dynamics
  • B60W2520/28—Wheel speed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2710/00—Output or target parameters relating to a particular sub-units
  • B60W2710/10—Change speed gearings
  • B60W2710/105—Output torque

Definitions

• the present invention relates to a method of rolling at a very low speed of a motor vehicle, on a terrain with low traction of the driving wheels, and a motor vehicle equipped with such a method.
• Motor vehicles may include a function of limitation of the slip of the driving wheels, called ASR (Anti Slip Regulation), which is one of the functions of the process of stability control of the vehicle, called ESP (Electronic Stabily Program).
• ASR Anti Slip Regulation
• ESP Electronic Stabily Program
• the stability control of the ESP vehicle uses sensors measuring the dynamics of the vehicle, and a brake control of the wheels, to brake some wheels of the vehicle and thus exert a torque on the vehicle around its center of gravity, allowing to modify its trajectory.
• the ASR drive wheel slip limitation function uses engine control and wheel brakes to limit the speed and the traction force of each drive wheel on the ground, by function of its adhesion. In this way, it is possible to maintain a certain optimum wheel slip of each wheel to maintain the best traction, and to ensure the traction and steering of the vehicle on very slippery floors, including for example mud or snow.
• this clutch For vehicles with a progressive coupling clutch between the engine and the transmission, once the start-up phase of the vehicle is completed, this clutch is kept closed without the possibility of slipping. But the engine must run at a minimum speed to avoid stalling and deliver sufficient torque.
• the transmission connected to this clutch also rotates with a minimum speed that usually drives the vehicle at speeds of the order of 12 to 13 km / h.
• the differential drive of an axle differentially distributes the movement received from the gearbox towards the two drive wheels of this axle, so that the sum of the speeds of the two wheels corresponds to the speed imposed on the output of the gearbox.
• the present invention is intended in particular to avoid these drawbacks of the prior art, and to provide a method for improving the adhesion of the drive wheels of a vehicle for rolling at a very low speed.
• a continuous rolling process at very low speed on a terrain with low adhesion for a motor vehicle comprising a controlled means of progressive coupling between the engine and the transmission, and a wheel slip limitation function driving which following wheel speed information motor, controls the braking of each drive wheel to limit their slippage, characterized in that for rolling at a very low speed, the function of limiting the slippage of the drive wheels also controls the controlled means of progressive coupling, to maintain a sliding continuous way of this means so as to reduce the average speed of the drive wheels, and get a small slip of these wheels.
• An advantage of this continuous rolling method at a very low speed is that, thanks to a permanent regulation of the sliding of the coupling means, and while keeping the minimum speed of rotation of the heat engine, the average rotation speed can be greatly reduced. driving wheels, and thus adapt to the very low speed of progression of the vehicle with a reduced slip of these wheels.
• the continuous low speed rolling method according to the invention may further include one or more of the following features, which may be combined with each other.
• the function of limiting the slippage of the drive wheels sends simultaneously to the engine a low engine speed setpoint.
• the low engine speed setpoint can generate a minimum speed of the engine to avoid stalling, while delivering to the drive wheels a sufficient traction torque.
• the very low speed rolling method emits a low engine speed instruction, and monitors the average speed of the driving wheels with respect to the speed of the vehicle, to evaluate the slippage and deduce a sliding setpoint for the control of the controlled progressive coupling means, in order to obtain an optimum slip value.
• the continuous rolling process at very low speed comprises a specific management of the transition between the running of the vehicle at a very low speed, and the normal operation with the coupling means closed, which is established to gradually return to the conditions of this normal march.
• the very low speed taxiing method can receive information from a control maneuvered by the driver to signal a state of adhesion of the track, this information allowing him to adapt internal operating parameters.
• the invention also relates to a motor vehicle having a continuous rolling process at very low speed on a terrain comprising a low adhesion, this rolling method further comprising any of the preceding features.
• the controlled means of progressive coupling between the engine and the transmission of the motor vehicle may include a clutch comprising disks whose tightening is controlled by an actuator.
• FIG. 1 is a diagram showing the main components of a vehicle comprising the continuous rolling process at very low speed according to the invention.
• the vehicle 1 comprises a heat engine 2 which drives by a clutch 4 comprising an automated control device, a gearbox 6 connected to the drive wheels 8 of the vehicle.
• the gearbox 6 is a robotic manual gearbox, comprising actuators for effecting the gear changes.
• the clutch comprises a torque transmission disk whose tightening is controlled by an actuator.
• the vehicle may comprise other transmission devices such as a double-clutch gearbox, a continuously variable gear transmission, or an automatic gearbox comprising planetary gears and a hydraulic input torque converter, the slip can be controlled.
• the vehicle may also include an auxiliary motor as an electric machine, in addition to the main thermal engine, to form a hybrid vehicle.
• a central control unit 10 comprising a computer and control laws stored in memory, receives information 20 from a braking system 12 comprising an independent brake control on each drive wheel 8.
• the received information 20 include in particular the speed of each driving wheel 8, delivered by speed sensors connected to each wheel.
• the control unit 10 comprises a method for monitoring the stability of the vehicle ESP, comprising a function of limiting the slippage of the driving wheels ASR.
• the control unit 10 may include other functions for assisting the driving of the vehicle, such as an anti-lock braking system called ABS (Anti-lock Braking System).
• control unit 10 monitors the rotational speed of the drive wheels 8 with the information received from the braking system 12, and compares them with theoretical speeds calculated from information from other sources, such as the speed of rotation of the non-drive wheels of the vehicle.
• the computer issues a brake pressure setpoint 22 for this wheel, delivered to the braking system 12, in order to slow it down.
• the control unit 10 sends to the heat engine 2 a set of engine speed 24, to limit its speed and avoid an increase in this speed due to the loss of traction of the drive wheel.
• the vehicle may further comprise a man-machine interface comprising a control 14 operated by the driver, for report to the control unit 10 a slippery track condition, including for example snow or ice.
• a slippery track condition including for example snow or ice.
• This additional information may include several levels of adhesion, allows the control unit 10 to choose the most appropriate laws to optimize control and get the best result.
• the speed obtained which is linked to that of the output of the clutch 4, is applied to the differential of the axle of the driving wheels 8.
• This speed of the differential is the average speed of the driving wheels 8.
• the method according to the invention operates as follows.
• the control unit 10 also transmits a sliding instruction 26 intended for the automated steering device of the clutch 4, to ask it to maintain a certain permanent slip in this clutch between the input speed which is that of the engine. 2, and that output applied to the gearbox 6.
• the sliding instruction is transformed taking into account the characteristics of the clutch 4, in position set for the clutch release bearing, which moves to effect a partial disengagement of this clutch.
• the driver activates the control 14 signaling a passage with little or possible adhesion of the ground.
• This command 14 gives the information to the control unit 10, which chooses the best control laws.
• the control unit 10 transmits a low engine speed instruction 24, close to its limit lower speed, and monitors the average speed of the driving wheels 8 with respect to the speed of the vehicle, to measure the skating of these driving wheels which must remain weak, according to a pre-established value.
• the control unit 10 then adjusts the controlled sliding setpoint 26 to be applied to the clutch 4, to obtain the slip value for optimizing the traction and steering of the vehicle.
• control unit 10 can intervene with the brake pressure setpoint 22, individually on each drive wheel 8 to limit its slip in case of lower adhesion of the wheel.
• Controlled sliding of the clutch 4 thus makes it possible to deliver to the drive wheels 8 a certain engine torque, with the ideal average rotation speed to obtain the best grip of these driving wheels.
• control unit 10 constantly adapts the sliding instruction 26 to obtain a similar evolution of the average speed of the drive wheels 8.
• the continuous rolling process at very low speed is then automatically deactivated.
• the driver can also signal the end of this passage by the control 14 if the vehicle is equipped, which allows to neutralize the rolling process at a very low speed and to avoid it delivers to the clutch 4 inappropriately , a sliding instruction 26 which could wear it.

Landscapes

• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Automation & Control Theory (AREA)
• Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
• Regulating Braking Force (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42139653

Family Applications (1)

Country Status (5)

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Citations (7)

• 2009
  • 2009-07-01 FR FR0954485A patent/FR2947507B1/fr not_active Expired - Fee Related
• 2010
  • 2010-06-28 BR BRPI1010112A patent/BRPI1010112A2/pt not_active IP Right Cessation
  • 2010-06-28 EP EP10745355A patent/EP2448783A1/fr not_active Withdrawn
  • 2010-06-28 WO PCT/FR2010/051340 patent/WO2011001094A1/fr active Application Filing
  • 2010-06-28 CN CN2010800295864A patent/CN102498021A/zh active Pending

Patent Citations (7)

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