Background technique
Conventionally rail pressure control logic mainly comprises following components: rail pressure actual value is measured also filtering, the calculating of rail pressure control desired value, rail pressure control device PID design, rail pressure control state machine design, rail pressure control final controlling element output control etc.Its basic thought is: pass through the value of feedback of suitable filtering algorithm as closed loop control according to the rail pressure value of actual measurement; Calculates rail pressure control deviation and input as PID, and controller output is determining the flow of high pressure oil pump output, this just and high pressure oil pump characteristics connect.High pressure oil pump mainly adopts PWM to control the aperture (electric current) of fuel gauging unit, and its parameter is control cycle and dutycycle, and the demand fuel supply flow rate of common rail pipe can be converted into the driving current of fuel gauging unit.Therefore, in the time that engine speed is greater than certain value, the flow of pump is directly determined by the aperture (electric current) of flow measurement unit, can calculate according to required galvanometer the control dutycycle of solenoid valve, this is known/and known.
At present, more advanced rail pressure control method is that rail pressure pre-control and feedback control are combined, pre-control is to calculate current reference according to engine speed, circulating fuel injection quantity and target rail pressure, and its Main Function is that retard time the retentive control device deviation of minimizing rail pressure control device is very little.Its essence is open loop control, PID controller tracking on this basis is compressed into row fine setting simultaneously, thereby make rail pressure control module realize good target rail pressure following feature, this be also known/known (referring to Patent Document: application number 201010601766.7)
; the actual resistance of considering fuel gauging unit controls valve can change with inside temperature; winding method and the assembly technology of control valve coil simultaneously; and when work power supply status fluctuation; it is wide than (target current) and control valve aperture electric current (actual current) generation relatively large deviation that capital causes working control valve to account for, and makes rail pressure control device pre-control produce larger setting deviation.So meticulousr control also should add the feedback control of fuel gauging unit controls valve electric current, what assurance control electric current was desirable follows goal-setting electric current.
In the prior art, in order to realize the electrical current of highi degree of accuracy control electromagnetic type proportional control valve, introduced current closed-loop control, and added Integral Processing in energising is controlled, wherein integration item initial value is set with two kinds of modes.A kind of mode is used control valve resistance value and calculates, another kind of target current and the actual current difference storage gain mode (referring to Patent Document: application number 200880120382.4) of adopting, and rear a kind of mode is the optimization to front a kind of mode.Current closed-loop control mode based on software approach, is difficult to follow accurately fast target current all the time.
Wherein in algorithm, relate to the setting of fuel gauging unit controls valve standard resistor, because the temperature change of control valve environment is very large, large to the ambient temperature difference of high load working procedure control valve from start-up course, working control valve resistance always departs from the standard resistor of setting, and deviation value always in fluctuation, this certainly will affect the performance of rail pressure control device under different operating environment.Meanwhile, software control method is due to the restriction of processor interrupt latency and computing capability, and response cycle is long, and current tracking control response is also slack-off, thereby can not make rail pressure pre-control reach optimum efficiency.
Summary of the invention
Technical problem to be solved by this invention is, provide a kind of to improve rail pressure adjusting function, realize rail pressure and follow fast, reduce as far as possible software algorithm complexity simultaneously, save motor rail pressure pre-control and feed back control system and control system and controlling method that processor hardware resource is object.
The technical solution adopted in the present invention is: a kind of motor rail pressure pre-control and feed back control system and control system and controlling method, wherein, motor rail pressure pre-control and feed back control system, include ECU unit, described ECU unit connects constant current control unit by inner communication interface, described constant current control unit connects respectively high pressure oil pump fuel gauging unit, PWM driver element and signal processing unit, described signal processing unit connects ECU unit by the digital signal interface of inside, ECU unit, described ECU unit connects PWM driver element by inner digital signal interface again.
The control system of motor rail pressure pre-control and feed back control system, to be formed by the rail pressure feedback control module of rail pressure pre-control module and reception rail pressure pre-control module output signal, described rail pressure pre-control module, for calculating current value corresponding to target rail pressure under specific engines operating mode, include reference current enquiry module and electric current distribution module; Described rail pressure feedback control module, be the feedback control that accounts for the adjusting realize target rail pressure of wide ratio by PWM driving pulse, include rail pressure deviation computing module, PID adjustment module, flow-electric current enquiry module, Current calculation module and account for the wide computing module that compares.
Described reference current enquiry module is by cyclic spray oil mass and the target rail pressure of motor mean speed, oil sprayer, according to the good Under Different Work Condition of Engine of prior demarcation and fuel gauging cell current value MAP corresponding to different target rail pressure, calculate pre-control current value; The pre-control current value that described electric current distribution module calculates reference current enquiry module is divided into two parts in proportion, the communication interface of the inside of the ECU unit of the launched machine rail pressure pre-control of a part and feed back control system sends to constant current control unit, and another part is directly outputed to rail pressure feedback control module.
Described rail pressure deviation computing module arrives PID adjustment module for the deviation of export target rail pressure and actual rail pressure, after the computing of PID adjustment module, output needs the fuel oil volume flow value of the input high pressure oil pump regulating, this flow value calculates feedback current value by flow-electric current enquiry module according to flow-current characteristics MAP of the fuel gauging unit of demarcating, this feedback current value and the current value that is input to rail pressure feedback control module from rail pressure pre-control module are input to Current calculation module simultaneously and are obtained feedback regulation electric current through add operation, and be input to account for and widely obtain PWM driving pulse than computing module and account for wide ratio, PWM driving pulse accounts for the wide PWM driver element that acts on motor rail pressure pre-control and feed back control system than PWM driving pulse after regulating after outside down trigger, for feedback regulation fuel gauging unit of flow, control the rail pressure of common rail pipe (15), common rail pipe (15) feeds back to rail pressure deviation computing module by rail pressure sensor actual rail pressure, complete the adjustment of a closed loop rail pressure.
Described accounting for is wide as follows than formula:
Account for wide ratio=(feedback regulation electric current × fuel gauging unit drives loop resistance/cell voltage) × 100%
Average resistance when fuel gauging unit drives loop resistance is got high pressure oil pump and normally worked.
Be used for the controlling method of the control system of motor rail pressure pre-control and feed back control system, comprise: by the query count current value corresponding to target rail pressure under specific engines operating mode of reference current, and current value is divided into two parts in proportion, the communication interface of the inside of the ECU unit of the launched machine rail pressure pre-control of a part and feed back control system sends to constant current control unit, and another part is added the feedback control for account for the adjusting realize target rail pressure of wide ratio by PWM driving pulse with feedback current.
The described query count that passes through reference current is current value corresponding to target rail pressure under specific engines operating mode, cyclic spray oil mass and the target rail pressure by motor mean speed, oil sprayer, according to the good Under Different Work Condition of Engine of prior demarcation and fuel gauging cell current value MAP corresponding to different target rail pressure, calculate pre-control current value.
Described is added the feedback control for account for the adjusting realize target rail pressure of wide ratio by PWM driving pulse with feedback current, actual rail pressure and target track are compressed into the calculating of row rail pressure deviation, and rail pressure deviation is carried out to PID computing, obtain needing the fuel oil volume flow value of the input high pressure oil pump regulating, again this flow value is calculated to feedback current value according to flow-current characteristics MAP of the fuel gauging unit of demarcating, this feedback current value and the described current value of cutting apart are in proportion obtained to feedback regulation electric current through add operation, calculate PWM driving pulse and account for wide ratio through accounting for wide ratio, PWM driving pulse accounts for the wide PWM driver element that acts on motor rail pressure pre-control and feed back control system than PWM driving pulse after regulating after outside down trigger, for feedback regulation fuel gauging unit of flow, control the rail pressure of common rail pipe, common rail pipe feeds back actual rail pressure by rail pressure sensor, being used further to rail pressure deviation calculates, complete the adjustment of a closed loop rail pressure.
Described accounting for is wide as follows than formula:
Account for wide ratio=(feedback regulation electric current × fuel gauging unit drives loop resistance/cell voltage) × 100%
Average resistance when fuel gauging unit drives loop resistance is got high pressure oil pump and normally worked.
Motor rail pressure pre-control of the present invention and feed back control system and control system and controlling method, realized the pre-control processing of rail pressure in hardware circuit mode, have the response time fast, the feature that followability is good; It is not subject to temperature variant impact of fuel gauging unit coil resistance completely, controls accurately; Reduce difficulty and the complexity of software control, saved the hardware resource of processor; Realize rail pressure and current double closed-loop control simultaneously, made ECU hardware resource and software resource obtain optimum combination.
Embodiment
Below in conjunction with embodiment and accompanying drawing, motor rail pressure pre-control of the present invention and feed back control system and control system and controlling method are described in detail.
Motor rail pressure pre-control of the present invention and feed back control system and control system and controlling method are mainly made up of hardware components (as shown in Figure 1) and software section (as shown in Figure 2).
Hardware components motor rail pressure of the present invention pre-control and feed back control system, be mainly used in providing the operation platform of software section, realize the current management to high pressure oil pump fuel gauging unit 4, it mainly comprises ECU unit 1, constant current control unit 3 and PWM driver element 6 three parts.
As shown in Figure 1, motor rail pressure pre-control of the present invention and feed back control system, include ECU unit 1, described ECU unit 1 connects constant current control unit 3 by inner communication interface 2, described constant current control unit 3 connects respectively high pressure oil pump fuel gauging unit 4, PWM driver element 6 and signal processing unit 7, described signal processing unit 7 connects ECU unit 1 by the digital signal interface 8 of 1 inside, ECU unit, and described ECU unit 1 connects PWM driver element 6 by inner digital signal interface 8 again.
Wherein, ECU unit 1 connects by inner communication interface 2 and constant current control unit 3, and sends target current instruction to constant current control unit 3; ECU unit 1 connects by inner digital signal interface 8 and PWM driver element 6 simultaneously, and sends PWM drive pulse signal to PWM driver element 6.
Both control signals of constant current control unit 3 and PWM driver element 6 are set up synchronized relation by signal processing unit 7, and signal processing unit 7 is mainly used in inner constant current control unit 3 control signal producing to change into and digital signal interface 8 compatible pulse signal mutually.
The constant current drive pulse signal (as shown in Figure 3) that signal processing unit 7 is exported, be input to the digital signal interface 8 of 1 inside, ECU unit, its trailing edge is for the internal interrupt of triggered digital signaling interface 8 respective pins, simultaneously from another pin output PWM drive pulse signal to PWM driver element 6.The generation of constant current drive pulse signal trailing edge each time all can trigger the generation of a PWM drive pulse signal, thereby guarantees both cycle synchronisation; The generation of constant current drive pulse signal trailing edge each time all can trigger the generation of a PWM drive pulse signal rising edge, thereby guarantees that both drivings are synchronous.
PWM drive pulse signal after synchronous can guarantee at constant current control unit 3, high pressure oil pump fuel gauging unit 4 to be carried out, on the basis of hardware current stabilization control (response is fast), high pressure oil pump fuel gauging unit 4 is carried out to afterflow control, realizes the electric current fine setting (as the rail pressure feedback module 14 in Fig. 2) to high pressure oil pump fuel gauging unit 4 by rail pressure closed loop control software.Thereby reach following fast and responding of rail pressure.
Software section mainly operates on hardware components ECU unit 1 platform, mainly realizes pre-control and feedback control management to target rail pressure, and it mainly comprises rail pressure pre-control module 19 and rail pressure feedback control module 18 two-part.
As shown in Figure 2, the control system of motor rail pressure pre-control of the present invention and feed back control system, is to be made up of the rail pressure feedback control module 18 of rail pressure pre-control module 19 and reception rail pressure pre-control module 19 output signals.
Described rail pressure pre-control module 19, for calculating current value corresponding to target rail pressure under specific engines operating mode, includes reference current enquiry module 10 and electric current distribution module 11.
Wherein, described reference current enquiry module 10 is by cyclic spray oil mass and the target rail pressure of motor mean speed, oil sprayer, according to the good Under Different Work Condition of Engine of prior demarcation and fuel gauging cell current value MAP corresponding to different target rail pressure,, calculate pre-control current value; The pre-control current value that described electric current distribution module 11 calculates reference current enquiry module 10 is divided into two parts in proportion, the communication interface 2 of the inside of the ECU unit 1 of the launched machine rail pressure pre-control of a part and feed back control system sends to constant current control unit 3, and another part is directly outputed to the Current calculation module 12 of rail pressure feedback control module 18.
The part that is sent to constant current driving unit 3 accounts for the very big part of pre-control current value, is automatically controlled by hardware circuit, and it is not subject to temperature variant impact of fuel gauging unit internal resistance and guarantees the stable control of driving current.The part that is directly outputed to Current calculation module 12 accounts for the small part of pre-control current value, for the adjusting basis amount (being 0 because the minimum of PWM driving pulse accounts for wide ratio) of rail pressure closed loop control is provided.
Described rail pressure feedback control module 18, be mainly the feedback control that accounts for the adjusting realize target rail pressure of wide ratio by PWM driving pulse, include rail pressure deviation computing module 17, PID adjustment module 16, flow-electric current enquiry module 14, Current calculation module 12 and account for wide than computing module 13.
Wherein, described rail pressure deviation computing module 17 deviations for export target rail pressure and actual rail pressure are to PID adjustment module 16, after 16 computings of PID adjustment module, output needs the fuel oil volume flow value of the input high pressure oil pump regulating, it may, for just, may be also negative that this flow value calculates feedback current value feedback current value by flow-electric current enquiry module 14 according to flow-current characteristics MAP of the fuel gauging unit of demarcating.This feedback current value and the current value that is input to rail pressure feedback control module 18 from rail pressure pre-control module 19 are input to Current calculation module 12 simultaneously and are obtained feedback regulation electric current through add operations, and be input to account for and widely obtain PWM driving pulse than computing module 13 and account for wide ratio, described accounting for is wide as follows than formula:
Account for wide ratio=(feedback regulation electric current × fuel gauging unit drives loop resistance/cell voltage) × 100%
Average resistance when fuel gauging unit drives loop resistance is got high pressure oil pump and normally worked.
PWM driving pulse accounts for the wide PWM driver element 6 that acts on motor rail pressure pre-control and feed back control system than PWM driving pulse after regulating after outside down trigger, for feedback regulation fuel gauging unit of flow, control the rail pressure of common rail pipe 15, common rail pipe 15 feeds back to rail pressure deviation computing module 17 by rail pressure sensor actual rail pressure, completes the adjustment of a closed loop rail pressure.
Interruption is produced by the timer in ECU unit 1, for setting the regulating cycle of rail pressure pre-control module 19 and rail pressure feedback control 18.
The constant current drive pulse signal trailing edge (as shown in Figure 1) that external interrupt is exported by hardware components signal processing unit 7 produces, and accounts for wide than the time-oriented sequential control (as shown in Figure 3) of PWM driving pulse after regulating for controlling PWM driving pulse.
The controlling method of the control system for motor rail pressure pre-control and feed back control system of the present invention, comprise: by the query count current value corresponding to target rail pressure under specific engines operating mode of reference current, and current value is divided into two parts in proportion, the communication interface 2 of the inside of the ECU unit 1 of the launched machine rail pressure pre-control of a part and feed back control system sends to constant current control unit 3, and another part is added the feedback control for account for the adjusting realize target rail pressure of wide ratio by PWM driving pulse with feedback current.
The described query count that passes through reference current is current value corresponding to target rail pressure under specific engines operating mode, cyclic spray oil mass and the target rail pressure by motor mean speed, oil sprayer, according to the good Under Different Work Condition of Engine of prior demarcation and fuel gauging cell current value MAP corresponding to different target rail pressure, calculate pre-control current value.
Described is added the feedback control for account for the adjusting realize target rail pressure of wide ratio by PWM driving pulse with feedback current, actual rail pressure and target track are compressed into the calculating of row rail pressure deviation, and rail pressure deviation is carried out to PID computing, obtain needing the fuel oil volume flow value of the input high pressure oil pump regulating, again this flow value is calculated to feedback current value according to flow-current characteristics MAP of the fuel gauging unit of demarcating, feedback current value may, for just, may be also negative.This feedback current value and the described current value of cutting apart are in proportion obtained to feedback regulation electric current through add operation, calculate PWM driving pulse and account for wide ratio through accounting for wide ratio, PWM driving pulse accounts for the wide PWM driver element 6 that acts on motor rail pressure pre-control and feed back control system than PWM driving pulse after regulating after outside down trigger, for feedback regulation fuel gauging unit of flow, control the rail pressure of common rail pipe 15, common rail pipe 15 feeds back actual rail pressure by rail pressure sensor, be used further to rail pressure deviation and calculate, complete the adjustment of a closed loop rail pressure.
Described accounting for is wide as follows than formula:
Account for wide ratio=(feedback regulation electric current × fuel gauging unit drives loop resistance/cell voltage) × 100%
Average resistance when fuel gauging unit drives loop resistance is got high pressure oil pump and normally worked.
Working principle of the present invention is as follows:
As shown in Figure 2, it is 95% pre-control current value that setting is here sent to the part of constant current driving unit 3, and the part that is directly outputed to Current calculation module 12 is 5% pre-control current value.
Timer in ECU unit 1 produces periodic down trigger, and program enters motor rail pressure pre-control and feedback control code.
First, software program enters rail pressure pre-control pre-control module 19, reference current enquiry module 10 is by cyclic spray oil mass and the target rail pressure of motor mean speed, oil sprayer, according to the good Under Different Work Condition of Engine of prior demarcation and fuel gauging cell current value MAP corresponding to different target rail pressure, calculate pre-control current value.Pre-control current value is divided into 95% pre-control current value and two parts of 5% pre-control current value in proportion by electric current distribution module 11,95% pre-control current value is sent to constant current driving unit 3 by the communication interface 2 (as shown in Figure 1) of ECU unit 1, and the pre-control of carrying out rail pressure realizes.
Other 5% pre-control current value is directly outputed to Current calculation module 12, and saves.
Subsequently, software program enters rail pressure feedback control module 18, rail pressure deviation is calculated 17 the difference of target rail pressure and actual rail pressure is input to PID adjustment module 16 as rail pressure deviation, after 16 computings of PID adjustment module, output needs the fuel oil volume flow value of the input high pressure oil pump regulating, and this flow value calculates feedback current value by flow-electric current enquiry module 14 according to flow-current characteristics MAP of the fuel gauging unit of demarcating.This feedback current value and the 5% pre-control current value being saved above are together input to Current calculation module 12 and obtain feedback regulation electric current through add operation, and be input to account for and widely obtain PWM driving pulse than computing module 13 and account for wide ratio, account for wide as follows than formula:
Account for wide ratio=(feedback regulation electric current * fuel gauging unit drives loop resistance/cell voltage) * 100%
Average resistance when fuel gauging unit drives loop resistance is got high pressure oil pump and normally worked.
The regulated value that PWM driving pulse is accounted for to wide ratio is kept in program variable, the break in service (as shown in Figure 1) of the constant current drive pulse signal trailing edge triggered digital signaling interface 8 that waiting signal puocessing module 7 is exported,
When after external interrupt response, adjusted PWM driving pulse is accounted for to wide ratio and directly act on PWM driver element 6, as the afterflow drive part of constant current driving unit 5, for feedback regulation fuel gauging unit of flow, control the rail pressure of common rail pipe 15, common rail pipe 15 feeds back to rail pressure deviation computing unit by rail pressure sensor actual rail pressure, completes a closed loop rail pressure and regulates.