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
  • B60W20/00—Control systems specially adapted for hybrid vehicles
• • 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
  • B60W10/08—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of electric propulsion units, e.g. motors or generators
• • 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
  • B60W2510/00—Input parameters relating to a particular sub-units
  • B60W2510/06—Combustion engines, Gas turbines
  • B60W2510/0638—Engine speed
  • B60W2510/0642—Idle condition
• • 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
  • B60W2510/00—Input parameters relating to a particular sub-units
  • B60W2510/10—Change speed gearings
  • B60W2510/1005—Transmission ratio engaged
  • B60W2510/101—Transmission neutral state
• • 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
  • B60W2520/10—Longitudinal 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
  • B60W2540/00—Input parameters relating to occupants
  • B60W2540/10—Accelerator pedal position
• • 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
  • B60W2540/00—Input parameters relating to occupants
  • B60W2540/10—Accelerator pedal position
  • B60W2540/103—Accelerator thresholds, e.g. kickdown
• • 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
  • B60W2540/00—Input parameters relating to occupants
  • B60W2540/12—Brake pedal position
• • 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
  • B60W2710/08—Electric propulsion units
  • B60W2710/081—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 invention is based on control methods for hybrid vehicles whose drive unit comprises both an electric motor and an internal combustion engine. Depending on the power request and driving situation, the internal combustion engine is switched on, the rotational energy of which is transmitted to the electric motor and / or used for locomotion of the vehicle.
• gearboxes and couplings provide the appropriate mechanical connection between the electric motor and the internal combustion engine.
• the application EP 1 571 315 A2 describes an idling number control of a drive unit with an internal combustion engine, which is driven during startup with a starter. There are two speeds provided, which are controlled sequentially.
• the idling speed of the electric motor is provided lower than the idling speed of the internal combustion engine so as to be able to use the advantages of the electric motor with respect to the internal combustion engine when idling.
• the handling is not affected, since the lowering of the idle speed of the electric motor below the idle speed of the engine is connected to a query that can be used to detect whether the idle speed can have any influence on the driving behavior.
• the query includes the assessment or query of the driving speed of the vehicle and / or the assessment or query of a desired torque.
• a desired torque it is checked whether the driver is requesting a certain speed or a specific torque for acceleration or whether a reduction of the speed for improving the efficiency is compatible with the desired torque.
• a desired torque which is entered by the driver via an accelerator pedal and / or a brake pedal, is compared with a torque minimum value, whereby it is determined whether the torque desired by the driver is negligible or zero. In particular, from the operation of the brake pedal is concluded that a reduction in the speed of the electric motor with the desired driving behavior is compatible.
• the speed of the drive shaft of the electric motor is referred to as the speed of the electric motor.
• This may be identical to the rotor speed of the electric motor or may be a multiple or a fraction thereof by an over or under reduction.
• both queries are connected via a logical OR operation, so that the idle target rotational speed is lowered below the idling rotational speed of the internal combustion engine when the driving speed or the desired torque are so low that the change in the driving behavior is brought about by the lowering to the idling speed.
• Target speed is negligible or can not be detected by the driver.
• the results of the two queries are combined via an AND link.
• it is determined whether the vehicle speed is zero, which corresponds to a vehicle speed threshold of 0 km / h.
• the electric motor is regulated to an idling setpoint speed that is below the idling minimum speed of the internal combustion engine.
• Such control corresponds to the usual control mechanisms in which a setpoint is set, an actual value is measured, and thereby the error, i. the difference between actual and setpoint is determined.
• the appropriate feedback of the error for influencing a manipulated variable ensures that the actual value is approximated to the setpoint until the actual value as a controlled variable is at the setpoint.
• Conventional control mechanisms that can also be used to implement the invention include a negative feedback of the error and a gain element P, a delay differential element D and / or an integral element I.
• the controllers used can thus P-, PI-, PD - or PID controller.
• the actual or desired size of the control are provided in the invention as the actual speed of the electric motor or as a target idle speed or setpoint speed of the electric motor, the manipulated variable of the control mechanism is realized in the invention as an excitation signal of the electric motor, for example as speed or strength a rotating E-field or as excitation current of one or more excitation windings of the electric motor.
• the speed and / or the strength of the rotating rotating field are used in asynchronous machines, in synchronous machines the strength or the speed of the rotating electrical field and in DC machines the current flowing through the field winding and the current flowing through the armature winding ,
• the speed in this context in relation to electrical machines comprises: angular velocity, rotational speed, predetermined rotational speed or predetermined rotational field frequency.
• the driving speed of the vehicle and the desired torque need not necessarily be exactly equal to zero in order to trigger a lowering of the idle setpoint speed. Instead, both desired torque and vehicle speed may be slightly above zero, or may have a value that is immaterial with respect to the change in driving behavior. Therefore, the vehicle speed threshold is preferably less than 0.1 km / h, below 5 km / h, or at a different speed value at which the change in driving performance is not essential by lowering the idling speed.
• the brake pedal position, the neutral position of the transmission or the accelerator pedal position can be detected. In particular, with minimal actuation of the accelerator pedal, according to the invention, it can be assumed that a reduction of the idle setpoint rotational speed has only an insignificant or tolerable driver influence on the driving behavior.
• the idle target speed may be lowered only slightly below the minimum idle speed of the engine, for example, from 600 rpm to 500 rpm, if a greater reduction in engine speed would result in a significant undesirable change in drivability.
• the magnitude of the reduction or the amount of the difference between idle setpoint speed and idle minimum speed of the internal combustion engine can therefore be provided depending on the driving speed and dependent on the desired torque, the difference being the lower the higher the desired torque or higher the driving speed is.
• a linear weighted sum or other function can be used which combines desired torque and driving speed in a suitable weighted manner and calculates from this idling setpoint speed or the magnitude of the reduction of the speed compared to the idling speed of the internal combustion engine.
• Desired torque and driving speed can thus be combined to a level that represents the sensitivity to speed reductions and the influence of the driving behavior detectable by the driver. If the sensitivity is low, for example, at standstill or coupled gearshift, then the speed can be very much lowered, for example, to zero, whereas at high sensitivity, for example, at a driving speed of about 2 km / h, the idle speed only slightly below Value is lowered, which is common for internal combustion engines, for example, at 400 to 500 revolutions per minute.
• a mechanical load may be provided which decelerates the rotational movement of the electric motor, for example a hydraulic torque converter.
• the torque that passes through the deceleration of the electric motor to the mechanical load can be used as another influencing control variable.
• the idle target speed is selected such that the torque output to the mechanical load does not exceed a certain torque output threshold, wherein the torque output directly depends on the speed of the electric motor.
• Such a control upshifts the idle target speed, the limit being defined by the torque output threshold.
• the difference between The actual torque output and the torque output threshold itself may be detected and used as a further weighted factor in the above-described calculation of the idle target speed.
• Hydraulic torque converters are used to couple the electric motor to the drive wheels of the vehicle with the torque converter intercepting jerky acceleration changes.
• a hydraulic torque converter output side and drive side of the torque converter are connected to each other via hydraulic fluid, so that at a speed difference, the hydraulic fluid, such as oil, connects to each other via a turbine.
• the hydraulic fluid such as oil
• the electric motor is controlled such that the speed difference is zero, and preferably the speed difference is non-zero, for example constant, and thus the idle speed slightly below the drive side speed, i. the turbine speed is tracked.
• the speed of the electric motor, and thus also the speed difference are controlled so that the torque output, i. the torque delivered by the electric motor to the torque converter has a predetermined value, for example a constant value greater than zero.
• the torque output may also have a value equal to zero, for example, with separate clutch.
• the torque output is maintained at a low, predetermined value by the speed of the electric motor is controlled relative to the rotational speed of the output side of the torque converter accordingly.
• the electric motor is operated as a generator in the regulation of the actual speed of the electric motor or the idle setpoint speed, so as to allow recuperation.
• Rekuperieren the kinetic energy of the vehicle is converted by braking via an electric motor operated as a generator into electrically storable energy and stored in an electrical memory.
• the electric motor provided for driving is operated as a generator, and the actual rotational speed of the electric motor (which results from the vehicle speed and the gear ratio between the wheel and the electric motor) is used as efficiently as possible for the generation of energy.
• the erf ⁇ ndungsgemä- sße method comprises detecting the actual speed of the electric motor.
• the idling setpoint speed of the electric motor in this case corresponds to the target of the control, ie the control variable, wherein the actual speed reflects the rotational speed of the rotor and the idle target speed reflects, for example, the rotating rotating field.
• the person skilled in the art is aware of the mode of operation of electrical machines that phase or speed differences between the rotor and stator lead to induced voltage, which can be dissipated as generated electrical power. Therefore, to achieve high generator performance, the difference between actual speed and idle setpoint speed is provided as high as possible, and preferably at low actual speeds, the set idle setpoint speed differs greatly from the actual speed of the electric motor, and at higher actual speeds a smaller difference is provided.
• the difference between idle setpoint speed and actual speed also directly influences the deceleration of the vehicle, so that preferably the difference is limited or regulated accordingly in order to limit the speed decrease. Further, the difference may depend on the state of charge of the electrical energy storage, so that at high charge state of the electrical energy storage only a small difference is provided to reduce the generator power, and at low state of charge of the electrical energy storage, the difference is provided such that there is a high generator power results in charging the electrical energy storage quickly.
• the recuperation efficiency is increased by opening an optional torque converter or clutch connecting it to the electric machine such that the torque delivered to the torque converter is negligible and nearly all of the rotational power is provided by the electric motor operated as a generator to be stored electrical energy is converted.
• further mechanical loads which decelerate the electric motor are taken into consideration, for example a transmission which requires a minimum input speed for maintaining the oil pressure.
• Other mechanical loads that require a minimum speed include, for example, air conditioning, alternators, or other devices that require minimum speed or minimum mechanical rotation power. Therefore, the regulatory procedure with a minimum Target speed provided, for example, at least 50, at least 100, at least 150 or at least 200 revolutions per minute, which is not exceeded. Preferably, the minimum speed is not exceeded even if other control components described above would require a reduction in the idle setpoint speed.
• a tolerance measure is entered by the driver that reflects the willingness to tolerate a change in drivability in favor of improved efficiency.
• Such an input may affect at least one of the thresholds or minimum values described above, for example the vehicle speed threshold below which the inventive control method may provide the idle target speed below the idle minimum speed of the internal combustion engine.
• the actuation threshold related to the actuation of the accelerator pedal of the vehicle which, if a high tolerance readiness is indicated, will not fully affect the operation of the accelerator pedal but only partially affect the idle speed and idle setpoint speed.
• operating parameters such as available range, battery state of charge, fuel tank level, etc., may be used to determine the magnitude of the influence of the vehicle Control method to determine the speed. If, for example, only little fuel remains in the tank, does the battery have a low charge state, or should the highest possible efficiency be achieved for other reasons, the control process can be adjusted by modifying the minimum values, minimum values or threshold values in such a way that the efficiency increased at the expense of a major change in driving behavior. Requires the driver's request that the control method according to the invention intervenes more in the idle control, although the efficiency is increased, but at the same time greatly changed the driving behavior. The amount of intervention by the control method in the regulation of the torque depends on the minimum values, minimum values and threshold values described above, which in turn depend on driver inputs.
• the control method can be realized by software, hardware or a combination thereof.
• the control method is preferably implemented at least partially in software that runs on a controller, wherein the controller is connected to an interface or comprises an interface via which control signals are output to or setpoint idle speed settings.
• Such an interface may further include inputs that detect rotational speeds, torque inputs, ie inputs of the desired torque, the driving speed or other operating variables of the hybrid vehicle described above.
• the guidance or tracking of the actual speed to the Idle setpoint speed which is specified by the inventive control method, can perform a conventional setpoint-actual value controller, which is also implemented as software, hardware or a combination thereof in the form of a microcontroller with memory, which implement in combination the control method according to the invention.
• sensors already present in the vehicle may be used, or a data interface belonging to a data processing unit to which at least one of the sensors is connected may be provided.
• the control method is suitable for serial hybrid drives and in particular for parallel hybrid drives.
• FIG. 1 shows speed curves which result from the method according to the invention and a speed curve according to the prior art which serves for comparison.
• FIG. 1 shows a speed curve that results when carrying out the control method according to the invention.
• the speed is plotted on the y-axis and denoted by N, whereas the time is plotted along the x-axis and denoted by t.
• the solid line in the diagram represents the actual rotational speed of an electric motor, as it occurs in the course of the embodiments of the control method according to the invention.
• the vehicle is driven at a constant high driving speed, which is linked to a constant high speed N fahr . From the time t 0 , the driving speed and thus also the actual rotational speed of the electric motor are reduced in accordance with the driver's request.
• the actual speed of the electric motor decreases continuously and reaches the idling minimum speed N min , VB , which corresponds to the minimum speed of the internal combustion engine at the time ti.
• N min the minimum speed of the internal combustion engine at the time ti.
• internal combustion engines basically have minimum speeds below which unstable operating conditions occur.
• the control method according to the invention provides from the time ti a further reduction, since erf ⁇ ndungshiel by the operation of the electric motor, the idling minimum speeds of an internal combustion engine need not be considered.
• the actual speed reaches an idling setpoint speed Nieeri, EM, which is set from time ti and is reached at time t 2 due to the inertia of the electric motor and the control.
• the difference between the idling minimum rotational speed N min , VB and the idling target rotational speed N lee ri, EM corresponds directly to the efficiency improvement that can be achieved with the method according to the invention.
• a very low idle target speed Ni ee r2 EM is provided, which is also controlled from the time ti and is tracked by the regulatory mechanism and reached at time t 3 . From Figure 1 it can be seen that the idle setpoint speed Ni ee r2, EM has a value that differs only slightly from zero, for example, to provide for certain consumers a minimum speed. The corresponding course of the actual speed is shown with N EM as a dashed line.
• a very low idle target speed is also provided, which, however, is slightly above the idle target speed Ni ee r2, EM .
• the course of the actual speed is shown in FIG. 1 with Nturb as a dotted curve.
• N EM is the speed of the output side
• Speed Nturb is the speed of the drive side.
• the output side refers to that connection of the torque converter, which is connected to the wheel, and the drive side of that terminal of the torque converter, which is connected to the electric motor.
• the speed of the output side N EM which is substantially zero from the time t 3 corresponds to a driving speed of substantially zero, and the small distance between the rotational speed Nturb and the time axis from the time t 3 corresponds to a residual speed with which the Electric motor rotates and with the electric motor runs against the torque converter. If the clutch between the electric motor and the wheel is opened from the time t 2 , no torque is output to the torque converter.
• a desired torque below a torque minimum value can be detected at the time t 0 , for example by decoupling the electric motor or by actuating the brake.

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• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Automation & Control Theory (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Hybrid Electric Vehicles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=40029369

Family Applications (1)

Country Status (6)

Families Citing this family (12)

Family Cites Families (7)

• 2007
  • 2007-10-05 DE DE102007047712A patent/DE102007047712A1/de active Pending
• 2008
  • 2008-09-23 JP JP2010527404A patent/JP5562244B2/ja not_active Expired - Fee Related
  • 2008-09-23 US US12/680,851 patent/US20100274423A1/en not_active Abandoned
  • 2008-09-23 EP EP08804596A patent/EP2197721A2/de not_active Withdrawn
  • 2008-09-23 WO PCT/EP2008/062679 patent/WO2009047114A2/de active Application Filing
  • 2008-09-23 KR KR1020107007207A patent/KR20100075472A/ko not_active Application Discontinuation

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