Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R16/00—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for
  • B60R16/02—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for electric constitutive elements
  • B60R16/03—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for electric constitutive elements for supply of electrical power to vehicle subsystems or for
• • 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
  • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
  • B60W2050/0001—Details of the control system
  • B60W2050/0019—Control system elements or transfer functions
  • B60W2050/0022—Gains, weighting coefficients or weighting functions
  • B60W2050/0024—Variable gains
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
  • F16H61/02—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used
  • F16H61/0202—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used the signals being electric
  • F16H61/0251—Elements specially adapted for electric control units, e.g. valves for converting electrical signals to fluid signals
  • F16H2061/0258—Proportional solenoid valve

Definitions

• Control unit for on-board voltage ripple - robust control of the electrical current of a control solenoid valve and associated method
• the invention relates to a motor vehicle control unit with a digital control circuit for Bordnetzwelltechnik- robust control of the electrical current of a solenoid valve for a motor vehicle hydraulic device with improved dynamic behavior on setpoint jumps of the setpoint current as Fuhrungsgrösse the control loop.
• a measuring element or a sensor is provided in the feedback branch of the respective control loop, with the aid of which the actual current is determined by the control solenoid valve and the input of the digital controller, in particular PID controller supplied. Due to the known characteristic field of the control solenoid valve can be closed by the measured electric current through the control solenoid valve to the hydraulic pressure of the hydraulic medium.
• the vehicle electrical system voltage or supply voltage of the respective motor vehicle may be unstable. In particular, it can be affected by various factors, even up to several volts.
• Fluctuations in the on-board supply voltage can also be transmitted to the electric current that flows through the respective control solenoid valve, so that there is an impingement of the controlled variable of the control circuit with disturbances.
• the perturbations are periodic, at unfavorable frequencies of the perturbations (resonant frequencies), undesired oscillations or even oscillations of the actual current, i. the output-side controlled variable of the current controller of the control loop come.
• a sluggish behavior of the regulator is undesirable in practice.
• a fast response of the controller is required in particular during circuits that are accompanied by a sudden setpoint current profile.
• the invention is based on the object to provide for improved adjustment of the electrical current of a control solenoid valve for a motor vehicle hydraulic device, a motor vehicle control unit with a digital or discrete control loop, which is largely robust to Bordnetzwoods- ripples and at the same time a sufficiently high dynamic response to fast Balancing of intended jumps in the setpoint current profile of the control solenoid valve has.
• the control unit according to the invention is particularly suitable as a transmission control for automatic transmission with high comfort demands on the export speed of desired switching operations at the same time high demands on the insensitivity to high electrical system fluctuations.
• the invention also relates to a method for reducing the influence of electrical system voltage ripples on the
• FIG. 1 shows a schematic representation of a transmission control as an exemplary embodiment of an inventive motor vehicle control device with a digital control circuit for adjusting the electrical coil current of the control solenoid valve of a motor vehicle hydraulic device
• FIG. 2 shows, on the basis of an exemplary current diagram, the control conditions in the digital control loop of the transmission control of FIG. 1, when in its feedback branch a fast and a slow correction filter are dynamically adjusted as a function of
• Correction filter is switched as a function of the D component of the output manipulated variable of the digital controller in the control loop.
• FIG. 1 shows, in a schematic representation, by way of example a transmission control CO as a control unit which controls the setting of the volume flow Q of a hydraulic medium, in particular a hydraulic fluid such as, for example, hydraulic oil
• a transmission control CO is preferably designed as an automatic transmission control unit for an automatic transmission.
• the electric actuator or the actuator EP has as a main component a control solenoid valve CV between its high-potential driver stage HSD and its low-potential driver stage LSD.
• By setting the coil current I of the control solenoid valve CV whose armature AN dips in a control cylinder at different depths in the volume flow Q of the hydraulic device HP.
• the armature AN in FIG. 1 is indicated merely by an arrow.
• the hydraulic device HP is in practice by at least one clutch CL and / or by at least one
• Hydraulic brake formed.
• the clutch CL or the hydraulic brake is in operative connection with a transmission TR of the motor vehicle.
• the coil current I of the control solenoid valve CV is assigned a specific hydraulic pressure of the volume flow Q in the hydraulic device HP via its characteristic field.
• the transmission controller CO a dynamic digital controller PC, in particular PID controller, in the forward branch FP of their digital control circuit CLS.
• the controller CV outputs a manipulated variable signal AS via the high-potential driver stage HSD to the control solenoid valve CV for the hydraulic device HP.
• the control solenoid valve CV and the hydraulic device HP forms part of the controlled system of the control circuit CLS.
• the measuring element GM is formed here in the exemplary embodiment by a galvanometer, which determines the respective present voltage at the control solenoid valve CV via a specific electrical resistance as a measure of the actual current CVS of the control solenoid valve CV. It converts the measured voltage values into corresponding, discrete actual current values CVS with the help of Ohm's law after corresponding A / D conversion. Possibly. can the
• the measured, discrete actual current values CVS are then forwarded by the measuring element GM to an adaptive correction filter KFI in the feedback branch FB whose filter time can be set dynamically.
• the correction filter KFI is symbolized in FIG. 1 by a dot-dashed frame. It is formed by a first, slower filter FI1 having a larger static filter time FT1 and a second, faster filter FI2 having a lower static filter time FT2. It therefore applies FTl> FT2.
• the first filter FIl is seated in the feedback coupling direction (viewed from the control loop output to the control loop input) in a first branch branch branch BR1 of the feedback coupling FB.
• the second filter FI2 is arranged in a second branch branch branch BR2 of the feedback path FB.
• the filter time FT1 or FT2 of the respective filter is preferably represented by the settling time of its step response.
• it is the time duration in which the step response of the respective filter increases from 0 dB to a constant value K dB. It identifies the time duration of the respective filter which requires it to respond to a level jump of an input signal with a corresponding level jump at the output.
• the larger the cutoff frequency of the respective filter the shorter its settling time.
• the greater the number of delay elements in the filter structure of the respective filter the lower the edge steepness of the step response of the respective filter. This is accompanied by a greater settling time.
• a filter with a short settling time can react faster than a filter with a longer settling time to an input-side level jump and follow this.
• the respective filter is designed, for example, as an averaging device, then its singling time duration is determined by the degree of its transfer function in the frequency domain and thus by the length of its discrete impulse response.
• the larger the number n of discrete input signal values used for averaging the slower the response of a discrete filter performing a discrete averaging over a window of given width n T for pending inputs with the clock period T will be and give an overall corrected discrete output at the output of the filter.
• such an averaging filter has a smaller filter time the smaller the number of discrete input values used for averaging and generating an average output value. This is accompanied by a short settling time of the filter, so that this filter can follow an input-side level jump faster.
• PT1 or PT2 elements can advantageously be used for these as simple low-pass filters.
• Other low-pass filters may also be expedient.
• the slower filter FI1 acts as a smoothing filter for the control variable CVS, which largely filters out disturbances due to on-board system voltage ripples and largely prevents them from being forwarded to the subtractor DIF.
• Ruckkoppelzweig FB inserted and is effective there for the measured actual current values CVS, which act as a control variable of the control loop CLS.
• the switching element SW is actuated by an analysis / control unit DA.
• the analysis / control unit DA evaluates the discrete ones
• Setpoint current values SS of the control loop CLS which are supplied to the upstream branch FP on the input side, in terms of their level dynamics.
• the actuation of the switching device SW by the analysis / control unit DA is indicated in FIG. 1 by a control arrow or effective arrow SL1.
• the analysis / control unit DA determines that the setpoint current SS is approximately constant, ie has a quasi-static profile, then it couples the branch load BR with the slow, first filter FI1 into the feedback branch FB by means of the switching element SW. Since this first filter FIl reacts with greater filter time FTl wear, it is largely insensitive and thus robust to disturbances of the control variable CVS, which are caused by electrical system voltage ripples or fluctuations. These are largely averaged out due to their long filter time and the larger number of measured, discrete actual current values taken into account in moving averaging. In this way, the first filter FIl sets at its output corrected control-sized CCV ready, which is largely cleansed by disturbances caused by vehicle voltage fluctuations.
• the analysis / control unit DA determines that the setpoint current SS briefly has a high level dynamic, it switches off the branch load BR1 of the first filter FI1 in the feedback branch FB by means of the switching element SW and instead adds the branch load BR2 of the second filter FI2 to the shorter filter time FT2 in the feedback branch FB. Due to its lower settling time, the filter FI2 allows the controlled variable CVS to follow rapid changes in the measured actual current CVS. Because a level jump of the setpoint current SS leads yes to a larger control deviation DIS, which converts the controller PC in a level jump of the manipulated variable AS.
• the fast-reacting correction filter FI2 thus allows the controller PC to quickly achieve a desired level jump of the
• Setpoint current SS to be converted into a corresponding level jump of the actual current I in the control solenoid valve CV.
• the entire control loop CLS in this case has high dynamics, i. a fast response to desired changes in the reference current waveform SS.
• FIG. 2 illustrates on the basis of a current diagram how the dynamic switching between the two filters FI1, FI2 takes place with their mutually different filter times FT1, FT2 as a function of level changes of the input-side setpoint current SS.
• the time t along which ordinates current values i are plotted.
• the time profile of the setpoint current SS is indicated by a solid line. It first proceeds in the period from t 0 to time t x substantially with the constant value Ul. At the time t x , it jumps to a new, higher level value Ol by a current drift value ⁇ S1 and keep it for one predeterminable length of time.
• the substantially constant flow on the level of the lower target current value Ul between the time to to the time t x is in the figure 2 with UK, the substantially constant current flow at the higher level level Ol after the time tx is designated therein with OK.
• the discontinuity between the lower constant target current profile UK and the upper target current profile OK is provided in FIG. 2 with the reference symbol ST.
• the analysis / control unit DA before the subtractor DIF at the input of the control circuit CLS observed according to the control clock of the control circuit CLS the level behavior of the setpoint current SS. As long as the analysis / control unit DA determines that level changes of the setpoint current SS are below a predetermined threshold .DELTA.L controls they switch SW in the feedback branch FB such that the slower
• Correction filter FIl with the larger filter time FTl is active. Then disturbances on the control variable CVS, which result from fluctuations in the vehicle electrical system voltage, can be filtered out, in particular averaged out, so that incorrect control of the digital controller PC are largely avoided.
• the disturbances with which the electrical coil current I of the control solenoid valve CV is acted upon by fluctuations in the vehicle electrical system voltages are indicated in FIG. 1 by a stinging arrow DSS.
• the slower filter FI1 is activated during the essentially constant level profile UK in the feedback branch FB.
• the upper and lower level fluctuation limits by which the setpoint current value U1 is allowed to vary at a predetermined threshold value ⁇ L to be evaluated by the analysis / control unit DA as substantially stationary or static are indicated by dash-dotted lines and denoted by the reference symbol EDI Mistake.
• the analysis / control unit DA determines the target current SS that by more than the threshold value .DELTA.L changes, as here, at time t x, it switches the Verzweigungsast BRI with the slower filter FIL in jerk path FB by means of the switching section SW, and for there the branching branch BR2 with the faster correction filter FI2 on. If the setpoint change .DELTA.S1 of the setpoint current SS occurs, this is reflected in a corresponding change of the control variable CVS. The Pegela minimum the control size CVS is now passed through the faster filter FI2 substantially and thus passes to the subtractor DIF.
• the analysis / control unit DA analyzes whether the predetermined threshold value ⁇ L is undershot by the level dynamic of the setpoint current SS. This is the case here in the exemplary embodiment from the time t e .
• the analysis / control unit DA then activates again the slower filter FI1 with the longer filter time FT1 by means of the switching element SW. That way you can from the static behavior of the control loop in turn disturbances of the control variable CVS, which are caused by fluctuations in the vehicle electrical system voltage, are filtered out by the correction filter FIl, so that the control behavior of the control circuit CLS remains largely unimpaired by these disturbances. This undesirable, unnecessary control processes are largely avoided by such disorders.
• the control circuit CLS thus sets the actual current I in the control solenoid valve stable to the desired setpoint current SS.
• multiple correction filters are preferably arranged parallel to one another in the feedback branch FB and are then activated in each case with the aid of a multiple changeover switch if their respective threshold value is exceeded by the determined pause level of the setpoint value stream.
• the so-called D component of the manipulated variable AS of the digital controller PC can be used as control parameter for the filter time of the individual correction filter KFI. This is indicated in FIG. 1 by a dot-dashed arrow D between the controller PC and the adaptive correction filter KFI.
• the D component D of the manipulated variable signal AS e.g. of a PID controller preferably determines according to the following relationship:
• D-part D C D (e new - e a it) / ⁇ t, where C 0 is a coefficient, e new the control deviation in the current control cycle r, e a the control deviation in the previous control cycle r-1, ⁇ t is the time duration between the previous and the current control cycle.
• a limiter TU is indicated by dash-dotted lines in the controller PC, which delimits the D component D to a lower and / or upper threshold T2, T1.
• an upper and a lower limit are set for the filter time of the adaptive correction filter, ie the filter time can be set variably between the upper and the lower limit.
• a limited D component F D is calculated according to the relationship ms
• the last factor is a scaling or
• the larger the differential component F D the greater the actual current value CVS (r) of the current control cycle r decreases the less the previous actual current value CVS (r-1) from the previous control cycle r-1 is taken into account.
• FIG. 3 illustrates how a dynamic change of the filter time of the individual adaptive correction filter KFI with the aid of the D component of the control signal AS of the controller PC is carried out in the same setpoint current waveform SS as in FIG.
• the time course of changes in the D-portion D of the manipulated variable signal AS is shown in phantom in FIG.
• At least one correction filter in the feedback branch is dynamically adjustable with regard to its filter time.
• a shorter filter time is selected to meet the requirements of the dynamics of the controller.
• the filter time of the at least one correction filter is chosen to be large enough to filter out the influence of disturbances due to fluctuations in the vehicle electrical system voltage as far as possible from the control variable.
• the current controller PC in the forward path of the control loop CLS in that the current controller PC determines the duty cycle of a PWM (pulse width modulated) signal as the manipulated variable AS changed. This in turn clocks over the PWM (pulse width modulated) signal
• End stage driver HSD (see Figure 1), the supply voltage of the control solenoid valve CV and thereby regulates the current I through the control solenoid valve CV.
• the current I is measured via a measuring resistor of the measuring sensor GM and is referred to as the actual current, i. as a rule-size CVS via the feedback branch FB to the subtractor DIF at the entrance of the forward path FP of the control loop CLS returned.
• the difference between the setpoint current SS and the actual current CVS is determined as a control deviation DIS.
• the control deviation DIS is given as an input variable to the digital controller PC, in particular PID controller.
• the PWM signal of the manipulated variable AS preferably has a constant frequency.
• the measured actual current CVS is determined by means of a slower filter such as eg FIl filtered in Figure 1.
• the threshold .DELTA.L can be suitably selected in practice equal to about 25mA.
• the carrying filter FI1 forms here in the exemplary embodiment of FIG. 1 and FIG. 2 preferably a moving average over 6 PWM periods. If the setpoint current has changed by more than the predefined threshold value ⁇ L within the time t, the faster filter FI2 is activated in order to achieve a high dynamic range of the
• a fast step response of the control loop is generated and at the same time with a stable behavior of the setpoint current any disturbances resulting from electrical system ripple, by switching to at least one filter sluggish filter behavior can be filtered out.
• the control loop then behaves essentially stable and thus comparable to the behavior with a durable wear, i. stationary filter in its feedback branch. High-frequency disturbance oscillations, which are superimposed on the control variable signal, are therefore largely suppressed and no longer enter into the determination of the control deviation.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Feedback Control In General (AREA)
• Magnetically Actuated Valves (AREA)
• Braking Systems And Boosters (AREA)
• Control Of Transmission Device (AREA)

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• 2006
  • 2006-03-28 DE DE102006014352A patent/DE102006014352B3/de not_active Expired - Fee Related
• 2007
  • 2007-02-14 DE DE502007001913T patent/DE502007001913D1/de active Active
  • 2007-02-14 WO PCT/EP2007/051446 patent/WO2007110273A1/de not_active Ceased
  • 2007-02-14 EP EP07704581A patent/EP2001711B1/de not_active Ceased
  • 2007-02-14 US US12/295,020 patent/US7596442B2/en active Active
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