CN204998601U - Automatically controlled power -assisted steering system - Google Patents

Abstract

The utility model relates to an automatically controlled power -assisted steering system, wherein, automatically controlled power -assisted steering system is including turning to mechanical unit, change valve opening regulating unit, oil pump regulating unit and ecu ECU, it can only change power -assisted steering through the rotational speed that changes oil pump driving motor to solve traditional automatically controlled hydrostatic steering helping hand system, and the aperture of commentaries on classics valve can only be according to the linear problem of adjusting of steering wheel corner, change the reasonable control of valve opening simultaneously, more be fit for the multiplex moreover lower requirement to the economic nature of auto steering, a steering system's the performance of following has further been improved when reducing the energy consumption.

Description

A kind of Electro-Hydraulic Power Steering System

Technical field

The utility model relates to automobile electrical control hydraulic steering system field, particularly a kind of Electro-Hydraulic Power Steering System.

Background technology

Electro-Hydraulic Power Steering System is a kind of by direct motor drive, the speed of a motor vehicle is monitored by car speed sensor, by controlling the opening degree of steering control valve, the rotating speed change oil liquid pressure of blade-type pump drive motor after ECU (Electrical Control Unit) ECU obtains data, realize the novel automobile power steering swivel system of the size adjustment of power steering dynamics, be widely used at present in automobile power steering.Compare traditional hydraulic power-assist steering system, the advantage such as economy in control feel when Electro-Hydraulic Power Steering System has a better galloping and dynamic response and driving process, because this system replaces driving engine Direct driver Hydraulic Pump with motor, the speed of a motor vehicle and steering handwheel rotating speed will affect the size of motor speed, when, steering wheel angle speed low in the speed of a motor vehicle is large, ECU response makes motor speed increase, and increases hydraulic fluid flow rate, increases power steering; Otherwise motor speed reduces, the power-assisted that system provides reduces.

But in the research of existing Electro-Hydraulic Power Steering System, on the one hand, can only according to the speed of a motor vehicle and steering-wheel torque determination motor speed, rotating speed again by controlling motor controls power torque, rotary valve aperture in hydraulic efficiency pressure system can only depend on steering wheel angle and carry out linear regulation, all can meet the requirement making motor turning energy consumption as far as possible little under being not suitable for multi-state, system architecture is improved significantly in addition in reduction energy consumption; On the other hand, the energy ezpenditure of system in motor turning process can not be considered at present to the research of Electro-Hydraulic Power Steering System optimal design aspect, simultaneously allowing for driver turn to impression.At present, carry out multi-objective optimization design of power for Mechanic system parameter and Hydraulic Pump parameter, make steering swivel system with less energy ezpenditure and ensure that the report that chaufeur obtains good road-holding property and steering feel there is not yet open.

Summary of the invention

For the problems referred to above, the utility model provides a kind of Electro-Hydraulic Power Steering System, and based on this system, according in the speed of a motor vehicle obtained by sensor, steering wheel angle, steering torque, automobile yaw velocity and road surface basis of signals, consider motor speed, rotary valve aperture, mechanical steering system parameter, the Electro-Hydraulic Power Steering System of Hydraulic Pump parameter and Multipurpose Optimal Method thereof, the utility model is achieved in that

A kind of Electro-Hydraulic Power Steering System, is characterized in that, comprise steering mechanical unit, rotary valve aperture regulon, oil pump regulon and electronic control unit ECU;

Described steering mechanical unit comprises the tierod that the steering handwheel, steering shaft, rack and pinion steering gear and the two ends that connect successively are connected with wheel, and tierod is provided with hydraulic actuating cylinder, and steering shaft is provided with torque sensor;

Described rotary valve aperture regulon comprises connected rotary valve and rotary valve regulates motor, hydraulic oil-returning pipeline is provided with between rotary valve and hydraulic reservoir, be provided with hydraulic actuating cylinder chargine line and hydraulic actuating cylinder oil return line between rotary valve and hydraulic actuating cylinder, hydraulic actuating cylinder both sides are provided with hydraulic pressure transducer element;

Described oil pump regulon comprises connected double-acting vane pump and oil pump drive motor; Double-acting vane pump is connected with rotary valve with hydraulic reservoir respectively, and the hydraulic oil exported by hydraulic reservoir is flow to hydraulic actuating cylinder chargine line and hydraulic actuating cylinder oil return line by rotary valve chargine line in rotary valve punishment;

Described electronic control unit ECU is connected with hydraulic pressure transducer element with torque sensor, receives the electric signal that they send, and regulates motor and oil pump drive motor to send control signal to rotary valve.

Further, in the utility model, described electronic control unit ECU is also connected with vehicle-mounted optical pickocff, receives the electric signal sent by vehicle-mounted optical pickocff.

Based on a Multipurpose Optimal Method for Electro-Hydraulic Power Steering System, concrete steps are as follows:

1) modeling software MATLAB-simulink is utilized, set up electric hydraulic power-assisted steering system model, Full Vehicle Dynamics model, and energy consumption math modeling, wherein electric hydraulic power-assisted steering system model comprises motor model, steering handwheel model, rack-and-gear model, steering pump model, rotary valve model, input and output shaft model, hydraulic position servo control model, tire model;

2) using steering swivel system energy consumption, steering feel and steering sensitivity as the power-steering Performance Evaluating Indexes of electric-controlled hydraulic, and set up the quantitative formula of three Performance Evaluating Indexes;

Wherein, the quantitative formula of steering feel is:

$\left\{\begin{array}{c}\frac{T_h\left(s\right)}{T_r\left(s\right)}=\frac{{\mathrm{qK}}_{TT}}{(m_r{r}_p^{2}q+n_1{J}_m{A}_p{r}_p)s^2+(B_r{\mathrm{qr}}_p^2+n_1{B}_m{A}_p{r}_p+\frac{{\mathrm{\ρq}}^2{\mathrm{n\η}}_v{A}_p^2{r}_p^2}{2C_q^2{A}^2})s+A_p{r}_p{\mathrm{KK}}_a{K}_s+{\mathrm{qK}}_{TT}}\\ q=2B\[\frac{1}{2}(R_2^2-R_1^2)\mathrm{\π}-(R_2-R_1)Zt\]\end{array}\right.$

$\left(1\right)$

In formula (1), T _hfor steering handwheel input torque, T _rfor the power torque of steering screw, m _rfor rack mass, r _pfor miniature gears radius, n ₁for steering swivel system steering wheel angle is to the transmitting ratio of front wheel angle, J _mfor the rotor inertia of motor and oil pump, A _pfor hydraulic cylinder piston area, B _rfor tooth bar damping coefficient, B _mfor the viscous damping coefficient of motor and oil pump, ρ is fluid density, and A is the oily discharge area of valve clearance, n _vfor the Volumetric efficiency of oil pump, C _qfor the coefficient of flow of valve clearance, K is motor power-assisted coefficient, K _afor steering assist motor torque factor, K _sfor torque sensor rigidity, k _tTfor the integral stiffness of steering shaft and torsion bar, q is capacity of pump, and B is stator thickness,

R ₂for stator major axis radius, R ₁for stator minor axis radius, Z is vane pump blade number, and t is blade thickness;

Steering sensitivity quantitative formula is:

$\left\{\begin{array}{c}\frac{\mathrm{\δ}\left(s\right)}{{\mathrm{\θ}}_s\left(s\right)}=\frac{A}{{\mathrm{Xs}}^2+Ys+Z+\frac{qd(k_1+k_2)}{n_2}\[\frac{a}{u}\frac{w_r\left(s\right)}{\mathrm{\δ}\left(s\right)}+\frac{\mathrm{\β}\left(s\right)}{\mathrm{\δ}\left(s\right)}+E_1\frac{\mathrm{\φ}\left(s\right)}{\mathrm{\δ}\left(s\right)}\]}\\ A=A_p{r}_p{\mathrm{KK}}_a{K}_s+K_{TT}q\\ X=m_r{r_p}^2{\mathrm{qn}}_2+n_1{J}_m{A}_p{r}_p{n}_2\\ T=(B_r{{\mathrm{qr}}_p}^2+n_1{B}_m{A}_p{r}_p+\frac{{\mathrm{\ρq}}^2{\mathrm{n\η}}_v{A_p}^2{r_p}^2}{2{C_p}^2{A_1}^2})n_2\\ Z=(A_p{r}_p{\mathrm{KK}}_a{K}_s+K_{TT}q)n_2-\frac{qd(k_1+k_2)}{n_2}\end{array}\right.---\left(2\right)$

In formula (2), δ (s) is the front wheel angle after Laplace transform, θ _ss () is the steering wheel angle after Laplace transform, β (s) is the yaw acceleration after Laplace transform, and φ (s) is the side slip angle after Laplace transform, w _rs () is the yaw velocity after Laplace transform, n is the rotating speed of double-acting vane pump, and n turns to output shaft to the transmitting ratio of front-wheel, a be automobile barycenter to front axle distance, u is automobile speed, d for for vehicle 1/2 wheelspan, E ₁for roll steer coefficient, k ₁, k ₂for front-wheel cornering stiffness;

Steering swivel system energy consumption quantitative formula is:

$\left\{\begin{array}{c}E=P_{ECU-loss}+P_{E-motorloss}+P_{pump-loss}+P_{v-loss}\\ E=U_A{I}_A+R_A{I}_A^2+\frac{U_s}{R_{elec}^2}+A_p{r}_p{\stackrel{\·}{\mathrm{\θ}}}_P\[\frac{\mathrm{\ρ}{({\mathrm{qnn}}_v+A_p{r}_p{\stackrel{\·}{\mathrm{\θ}}}_P)}^2}{8C_{q}nL{(w+\frac{{\mathrm{RK}}_c\mathrm{\θ}}{K_c+K_n})}^2}-\frac{\mathrm{\ρ}{({\mathrm{qnn}}_v-A_p{r}_p{\stackrel{\·}{\mathrm{\θ}}}_P)}^2}{8C_{q}nL{(w-\frac{{\mathrm{RK}}_c\mathrm{\θ}}{K_c+K_n})}^2}\]\end{array}\right.---\left(3\right)$

In formula (3), E is steering swivel system total energy consumption power, P _eCU-lossfor ECU consumed power, P _e-motorlossfor motor wasted power, P _pump-lossfor Hydraulic Pump loss power, P _v-lossfor rotary valve loss power; U _afor the available voltage of hydraulic pump drive motor, I _afor Motor Current, R _afor the load resistor of armature current, R _elecfor the resistance on non-armature current, U _sfor power line voltage, L is rotary valve Opening length, and w is rotary valve A/F, K _cfor steering shaft rigidity, K _nfor torque sensor rigidity;

3) with steering feel and steering swivel system energy consumption for optimization aim, steering sensitivity is system constraints, sets up Electro-Hydraulic Power Steering System Model for Multi-Objective Optimization, and objective function f (x) that Electro-Hydraulic Power Steering System is optimized is:

$\left\{\begin{array}{c}f\left(x\right)=\frac{k_1}{f\left(x_1\right)}+k_{2}f\left(x_2\right)\\ f\left(x_1\right)=\frac{1}{2{\mathrm{\π\ω}}_0}{\∫}_0^{{\mathrm{\ω}}_0}|\frac{T_h\left(s\right)}{T_r\left(s\right)}{{|}_{s=j\mathrm{\ω}}}^{2}d\mathrm{\ω}\\ f\left(x_2\right)=P_{motor-loss}+P_{v-loss}\end{array}\right.---\left(4\right)$

In formula (4): road feel function f (x ₁) be information of road surface effective frequency range (0, ω ₀) frequency domain energy aviation value, ω in prioritization scheme ₀=40Hz; Energy consumption function f (x ₂) be the waste of power of system motor and the waste of power of rotary valve;

The constraint condition of Electro-Hydraulic Power Steering System optimization is:

$f\left(x_3\right)=\frac{1}{2{\mathrm{\π\ω}}_0}{\∫}_0^{{\mathrm{\ω}}_0}|\frac{{\mathrm{\ω}}_r\left(s\right)}{{\mathrm{\θ}}_h\left(s\right)}{|}^{2}d\mathrm{\ω}---\left(5\right)$

ω in optimizing process ₀=40Hz, and formula (5) function meets 0.0008≤f (x ₃the constraint condition of)≤0.0099;

4) by stator thickness B, the rotor inertia J of motor and oil pump _m, torque sensor stiffness K _s, Hydraulic Pump rotating speed n, rotary valve rotational angle theta is as the design variable of Electro-Hydraulic Power Steering System;

5) Optimization Software is utilized: isight, the improvement Memetic intelligent algorithm merging cuckoo algorithm is adopted to be optimized the mechanical parameter in formula (1)-(4), hydraulic system parameters, draw optimum pareto disaggregation according to optimum results, and choose optimum solution of compromising;

6) power consumption values before separating power consumption values corresponding to each parameter and optimizing of being compromised by the optimum of acquisition compares, if lower than the power consumption values before optimization, then thinks and optimizes effectively.

Further, in the utility model, step 5) the improvement Memetic intelligent algorithm concrete steps of described fusion cuckoo algorithm are as follows:

51) encode:

According to span and the constraint condition restriction of design variable, obtain the feasible solution data of solution space, and be expressed as the floating type string structure data of search volume, namely the various combination of these string structure data constitutes different feasible solutions;

52) initial population is produced:

Initial population is random generation, for the N=0 moment, and random generation M feasible solution, the concrete random feasible solution X produced _ifor:

X _i＝rand(0,1)(X _max-X _min)+X _min(6)

X _maxfor the coboundary of feasible solution scope, X _minfor the lower boundary of feasible solution scope;

53) degree of adaptability calculates:

The feasible solution obtained is substituted into objective function, and the target function value obtained corresponds to degree of adaptability, and target function value is more excellent corresponding individual as defect individual;

54) colony Meme cooperates,

From previous generation colony, choose M defect individual, enter next iteration process, select probability as shown in the formula:

$p_i=\frac{\left|f\left(X_i\right)\right|}{\underset{n=1}{\overset{M}{\Σ}}\left|f\left(X_n\right)\right|}---\left(7\right)$

Individual to initial M of producing, calculate according to following Crossover Operator, produce new population:

$\begin{array}{c}{P_1}^{nex}=w_1{P}_1+(1-w_1)P_2\\ {P_2}^{nex}=w_2{P}_2+(1-w_2)P_1\end{array}---\left(8\right)$

In formula: P ₁, P ₂for two father's individualities of random selecting from population; for the filial generation by producing after crossover operator computing is corresponding new individual; w ₁, w ₂for [0,1] the upper random random number produced;

In the new population that hybridization computing produces, the mutation operator provided by following formula carries out mutation operation, chooses several body:

$V^{new}=\left\{\begin{array}{cc}V+(b_{up}-V){\[r(1-t)\]}^2,& sign=0\\ V-(V-b_{lb}){\[r(1-t)\]}^2,& sign=1\end{array}\right.---\left(9\right)$

In formula: V is the Mutation parameter chosen; V ^newfor the parameter after variation; Sign gets 0 or 1 at random; b _up, b _lbbe respectively the upper bound and the lower bound of parameter value; R is [0,1] upper random random number produced; T=g _c/ g _mfor the mark of Evolution of Population, wherein, g _cthe algebraically that population works as evolution, g _mit is the maximum evolutionary generation of population;

55) Local Search, to step 54) in all carry out Local Search after each crossover and mutation, cuckoo algorithms are adopted to all individualities in population, using the solution that obtains through genetic algorithm as initial population, calculate degree of adaptability, then Bird's Nest position upgraded, by following formula:

$K_{g+1,i}=K_{g,i}+\∂\frac{\mathrm{\φ}\×u}{|v{|}^{\frac{1}{\mathrm{\β}}}}(K_{g,i}-K_{best})---\left(10\right)$

In formula in (10), K _g,irepresent that i-th Bird's Nest is in the Bird's Nest position in g generation, K _bestfor current optimal solution, for constant;

$\begin{array}{cc}\frac{\mathrm{\&phi;}\&times;u}{|v{|}^{\frac{1}{\mathrm{\&beta;}}}}-u=t^{-\mathrm{\&beta;}}& 1<\mathrm{\&beta;}\&le;3\end{array},---\left(11\right)$

Obey Lay dimension probability distribution, u.v obeys standard normal distribution;

Wherein, $\mathrm{\&phi;}={\left\{\frac{\mathrm{\&Gamma;}(1+\mathrm{\&beta;})sin\left(\frac{\mathrm{\&beta;}}{2}\mathrm{\&pi;}\right)}{\mathrm{\&Gamma;}\left(2^{\frac{\mathrm{\&beta;}-1}{2}}\frac{1+\mathrm{\&beta;}}{2}\mathrm{\&beta;}\right)}\right\}}^{\frac{1}{\mathrm{\&beta;}}}---\left(12\right)$

Relatively relevance grade, retains the new nest of relevance grade higher than previous generation Bird's Nest;

Again according to after the probability dropping partial solution of 5%, random walk is adopted to regenerate the new explanation of equal number:

Ω _g+1,i＝Ω _g,i+rand(0,1)(Ω _g,j-Ω _g,k)(13)

Ω in formula (13) _g,j, Ω _g,kfor two random nests in g generation, make lower generation nest quantitatively be consistent with the previous generation, enter next round optimizing, select new nest after being supplemented, degree of adaptability calculates.Until meet greatest iteration number, complete individual Meme cooperation Local Search;

56) optimize through genetic algorithm, cuckoo algorithm loop iteration, obtain the optimal solution that degree of adaptability is the highest;

57) check stop condition whether to meet, if meet greatest iteration number, carry out next step decoding; No, go to step 53) produce population of future generation continuation optimization;

58) decode, be optimized the optimum pareto disaggregation obtained;

59) designer chooses satisfied optimum compromise solution.

The instruction that rotary valve regulates motor to send according to electronic control unit ECU, controls rotary valve and regulates motor regulating rotary valve opening, flowed by the hydraulic oil exported, thus form pressure reduction in hydraulic actuating cylinder both sides, provide wheel steering power-assisted through double-acting vane pump in rotary valve punishment.

The instruction that oil pump drive motor sends according to electronic control unit ECU, regulates oil pump drive motor rotating speed, thus control double-acting vane pump pump oil mass, and with the size of rotary valve aperture regulon Collaborative Control power steering.

The beneficial effects of the utility model are:

(1) electric-controlled hydraulic steering swivel system of the present utility model changes on power steering basis at existing steering swivel system by the rotating speed changing oil pump drive motor, add rotary valve aperture regulon, the hydraulic oil exported through double-acting vane pump is flowed in rotary valve punishment, thus provide power steering at hydraulic actuating cylinder both sides formation pressure reduction, the size of itself and oil pump regulon Collaborative Control power steering, the rotary valve aperture solving existing electric-controlled hydraulic steering boost system can only depend on the problem that steering wheel angle carries out linear regulation; Meanwhile, the conservative control of rotary valve aperture, is more suitable for the requirement to motor turning economy under multi-state, further increases the trace performance of steering swivel system while reducing energy consumption.

(2) the utility model considers the energy ezpenditure of system in motor turning process, and allowing for driver turn to impression, propose the main performance critical for the evaluation of Electro-Hydraulic Power Steering System, and set up its quantitative formula; With motor turning road feel, steering sensitivity, steering swivel system power consumption for optimization aim, multi-objective optimization design of power is carried out to the mechanical parameter of Electro-Hydraulic Power Steering System, hydraulic system parameters, makes steering swivel system ensure that chaufeur obtains good steering feel with less energy ezpenditure.

(3) the electric-controlled hydraulic steering swivel system Multipurpose Optimal Method that the utility model proposes, implants the local search procedure of Memetic algorithm by cuckoo algorithm, propose the Memetic Stochastic Optimization Algorithms improved.The method adopts genetic mechanism to carry out the breadth first search of overall Meme colony, cuckoo algorithm is adopted to carry out the Local Search of individual Meme, realize evolving and the cooperative development based on the local discovery learning of individuality based on the overall situation of population, the degree of depth and the range searched for of globally optimal solution of the search of algorithm locally optimal solution can be improved largely, thus promote the preceence of optimal solution, improve multiple-objection optimization efficiency and the effect of optimization of Electro-Hydraulic Power Steering System.

Accompanying drawing explanation

Fig. 1 is Electro-Hydraulic Power Steering System constructional drawing;

In figure, 1, steering handwheel; 2, torque sensor; 3, steering shaft; 4, rack and pinion steering gear; 5, wheel; 6, hydraulic actuating cylinder oil return line; 7, hydraulic actuating cylinder; 8, hydraulic cylinder piston; 9, hydraulic actuating cylinder chargine line; 10, rotary valve oil return line; 11, hydraulic reservoir; 12, double-acting vane pump; 13, oil pump drive motor; 14, rotary valve chargine line; 15, pump oil motor speed control signal; 16, electronic control unit ECU; 17, vehicle speed signal; 18, lateral acceleration signal; 19, longitudinal acceleration signal; 20, vehicle-mounted optical sensor signals; 21, steering wheel angle signal; 22, yaw rate signal; 23, hydraulic actuating cylinder pressure difference signal; 24, adjustment motor control signal is forwarded; 25, torque sensor signal; 26, rotary valve; 27, adjustment motor is forwarded; 28, tierod.

Fig. 2 is Electro-Hydraulic Power Steering System optimization method diagram of circuit.

Fig. 3 is the improvement Memetic intelligent algorithm diagram of circuit merging cuckoo algorithm.

Detailed description of the invention

Embodiment 1 Electro-Hydraulic Power Steering System

As shown in Figure 1, a kind of Electro-Hydraulic Power Steering System, comprises steering mechanical unit, rotary valve aperture regulon, oil pump regulon and electronic control unit ECU16;

Wherein, steering mechanical unit comprises the transverse axis 28 that the steering handwheel 1, steering shaft 3, rack and pinion steering gear 4 and the two ends that connect successively are connected with wheel, and transverse axis is also provided with hydraulic actuating cylinder 7, and hydraulic fluid pressure cylinder piston 8 is arranged in hydraulic actuating cylinder 7;

Rotary valve aperture regulon comprises connected rotary valve 26 and rotary valve regulates motor 27, is provided with hydraulic oil-returning pipeline 10, and is provided with hydraulic actuating cylinder chargine line 9 and hydraulic actuating cylinder oil return line 6 between rotary valve 26 and hydraulic actuating cylinder 7 between rotary valve 26 and hydraulic reservoir 11; Hydraulic actuating cylinder both sides are also provided with hydraulic pressure transducer element, its by hydraulic pressure difference signal transmission to electronic control unit ECU;

Oil pump regulon comprises connected double-acting vane pump 12 and the oil pump drive motor 13 of drive vane pump; Double-acting vane pump 12 is connected with rotary valve 26 with hydraulic reservoir 11 respectively, the hydraulic oil exported by hydraulic reservoir 11 is flowed in rotary valve punishment by rotary valve chargine line 14, part hydraulic oil flows into hydraulic actuating cylinder 7 side by hydraulic actuating cylinder chargine line 9, pressure reduction is produced in hydraulic actuating cylinder 7 both sides, promote hydraulic cylinder piston 8 to move, the hydraulic oil of hydraulic actuating cylinder 7 opposite side flows back to rotary valve 26 by oil return line 6 again, finally flows back to hydraulic reservoir 11;

Electronic control unit ECU16 can be divided into connected traffic information COMPREHENSIVE CALCULATING module, rotary valve aperture adjustment module and Oil pump electrical machinery rotational speed control module, rotary valve aperture adjustment module and Oil pump electrical machinery rotational speed control module regulate motor 27 to be connected with oil pump drive motor 13 with rotary valve respectively, send control signal to them, traffic information COMPREHENSIVE CALCULATING module is connected with hydraulic pressure transducer element with the torque sensor 2 be located on steering shaft 3, accept the electronic signal that they send, receive simultaneously and be distributed in automobile car speed sensor everywhere, acceleration pick-ups etc. obtain vehicle speed signal 17, yaw rate signal 22, steering wheel angle signal 21, torque sensor signal 25, the road surface signal 20 that vehicle-mounted optical pickocff detects, lateral acceleration signal 18, longitudinal acceleration signal 19, calculate through optimizing, obtain the optimal control rotating speed of Oil pump electrical machinery and the optimum aperture of rotary valve, and signal is passed to respectively oil pump drive motor 13 and rotary valve adjustment motor 27, simultaneously, by the hydraulic pressure transducer element installed in hydraulic actuating cylinder both sides using the pressure reduction of hydraulic steering cylinder as feedback signal, compare with desirable pressure reduction, calculating through electronic control unit ECU16 is added in the desired speed of oil pump drive motor 13 and the desirable aperture of rotary valve 26 by the compensation corner of the compensating rotational speed of oil pump drive motor 13 and rotary valve respectively, transmit oil pump drive motor speed controling signal 15 by electronic control unit ECU16 and forward and regulate motor control signal 24, power steering reaches ideal value, make Electro-Hydraulic Power Steering System while completing power steering, also the feel of allowing for driver.

When steering handwheel 1 rotates, electronic control unit ECU16 regulates motor 27 to transmit rotary valve according to the sensory information that torque sensor 2 sends to rotary valve and regulates motor control signal 24, control rotary valve 26 and rotate certain angle, by the hydraulic oil shunting of pumping through double-acting vane pump 12, be connected with hydraulic actuating cylinder 7 both sides through hydraulic actuating cylinder oil return line 6, hydraulic actuating cylinder chargine line 9, pressure reduction is formed, to provide wheel 5 power steering in hydraulic actuating cylinder 7 both sides; Meanwhile, electronic control unit ECU16 also transmits pump oil motor speed control signal 15 fuel feed pump drive motor 13, and the flow of hydraulic control oil, with the combined action of rotary valve aperture regulon, regulates the size of power steering.

The present embodiment hydraulic and electronic control steering system is compared traditional automatically controlled hydraulic steering power-assisted system and is just changed power steering by changing oil pump drive motor 13 rotating speed, the aperture of rotary valve 26 is just by steering wheel angle linear regulation, Electro-Hydraulic Power Steering System considers electric liquid factor, make both work in coordination with the adjustment of power steering size, reduce and turn to energy consumption under original scheme.

In the present embodiment, electronic control unit ECU16 is also connected with vehicle-mounted optical pickocff 20, motor turning operation is prejudged by the feedback of road pavement information, when nothing turns to, electronic control unit ECU16 controls rotary valve 26 aperture in certain angle, oil pump drive motor 13 also runs with lower rotating speed, actv. ensure that the followability of steering operation again while energy-conservation, shorten the response time of steering operation, compared to electronically controlled hydraulic system in the past, rotary valve corner no longer only depends on steering wheel angle, shorten the response time of steering swivel system, while reducing energy consumption, improve the followability turned to.

Embodiment 2 Multipurpose Optimal Method

In the present embodiment, the modeling software used is MATLAB-simulink, and Optimization Software is isight;

The present embodiment adopts system described in embodiment 1 to carry out multiple-objection optimization calculating, and Fig. 2 is this Multipurpose Optimal Method flow process block schematic illustration, and concrete steps are as follows:

Step 1: according to " research of automobile power steering pump and control cock " (Shandong university of science etc., colleges and universities' natural sciences research), " design study of Electro-Hydraulic Power Steering System " (monarch Mr. Zhang, Jiangsu University), " electric hydraulic power-assisted steering system control policy and energy consumption analysis method thereof " (Su Jiankuan etc., machine design and manufacture) method disclosed in document, set up electric hydraulic power-assisted steering system model, Full Vehicle Dynamics model, and energy consumption model, wherein electric hydraulic power-assisted steering system model comprises motor model, steering handwheel model, rack-and-gear model, steering pump model, rotary valve model, input and output shaft model, hydraulic position servo control model, tire model, by setting up steering swivel system model, energy consumption model, steering swivel system for subsequent step emulates and optimizes and lays the foundation,

Step 2: consider the energy ezpenditure in motor turning process, choose steering swivel system energy consumption, steering feel and steering sensitivity as the power-steering main performance critical for the evaluation of electric-controlled hydraulic, set up the quantitative formula of three Performance Evaluating Indexes;

Carried out the steering feel of analysis system by the impact of the excitation on steering gear on steering handwheel holding moment, the quantitative formula calculating Electro-Hydraulic Power Steering System road feel is:

$\left\{\begin{array}{c}\frac{T_h\left(s\right)}{T_r\left(s\right)}=\frac{{\mathrm{qK}}_{TT}}{(m_r{r}_p^{2}q+n_1{J}_m{A}_p{r}_p)s^2+(B_r{\mathrm{qr}}_p^2+n_1{B}_m{A}_p{r}_p+\frac{{\mathrm{\&rho;q}}^2{\mathrm{n\&eta;}}_v{A}_p^2{r}_p^2}{2C_q^2{A}^2})s+A_p{r}_p{\mathrm{KK}}_a{K}_s+{\mathrm{qK}}_{TT}}\\ q=2B\&lsqb;\frac{1}{2}(R_2^2-R_1^2)\mathrm{\&pi;}-(R_2-R_1)Zt\&rsqb;\end{array}\right.---\left(1\right)$

In formula (1), T _hfor steering handwheel input torque, T _rfor the power torque of steering screw, m _rfor rack mass, r _pfor miniature gears radius, n ₁for steering swivel system steering wheel angle is to the transmitting ratio of front wheel angle, J _mfor the rotor inertia of motor and oil pump, A _pfor hydraulic cylinder piston area, B _rfor tooth bar damping coefficient, B _mfor the viscous damping coefficient of motor and oil pump, ρ is fluid density, and A is the oily discharge area of valve clearance, n _vfor the Volumetric efficiency of oil pump, C _qfor the coefficient of flow of valve clearance, K is motor power-assisted coefficient, K _afor steering assist motor torque factor, K _sfor torque sensor rigidity, k _tTfor the integral stiffness of steering shaft and torsion bar, q is capacity of pump, and B is stator thickness,

R ₂for stator major axis radius, R ₁for stator minor axis radius, Z is vane pump blade number, and t is blade thickness;

Steering sensitivity reflects the speed that steering swivel system responds Driver Steering Attention, and steering sensitivity quantitative formula can be expressed as:

$\left\{\begin{array}{c}\frac{\mathrm{\&delta;}\left(s\right)}{{\mathrm{\&theta;}}_s\left(s\right)}=\frac{A}{{\mathrm{Xs}}^2+Ys+Z+\frac{qd(k_1+k_2)}{n_2}\&lsqb;\frac{a}{u}\frac{w_r\left(s\right)}{\mathrm{\&delta;}\left(s\right)}+\frac{\mathrm{\&beta;}\left(s\right)}{\mathrm{\&delta;}\left(s\right)}+E_1\frac{\mathrm{\&phi;}\left(s\right)}{\mathrm{\&delta;}\left(s\right)}\&rsqb;}\\ A=A_p{r}_p{\mathrm{KK}}_a{K}_s+K_{TT}q\\ X=m_r{r_p}^2{\mathrm{qn}}_2+n_1{J}_m{A}_p{r}_p{n}_2\\ Y=(B_r{{\mathrm{qr}}_p}^2+n_1{B}_m{A}_p{r}_p+\frac{{\mathrm{\&rho;q}}^2{\mathrm{n\&eta;}}_v{A_p}^2{r_p}^2}{2{C_p}^2{A_1}^2})n_2\\ Z=(A_p{r}_p{\mathrm{KK}}_a{K}_s+K_{TT}q)n_2-\frac{qd(k_1+k_2)}{n_2}\end{array}\right.---\left(2\right)$

In formula (2), δ (s) is the front wheel angle after Laplace transform, θ _ss () is the steering wheel angle after Laplace transform, β (s) is the yaw acceleration after Laplace transform, and φ (s) is the side slip angle after Laplace transform, w _rs () is the yaw velocity after Laplace transform, n is the rotating speed of double-acting vane pump, and n turns to output shaft to the transmitting ratio of front-wheel, a be automobile barycenter to front axle distance, u is automobile speed, d for for vehicle 1/2 wheelspan, E ₁for roll steer coefficient, k ₁, k ₂for front-wheel cornering stiffness;

Steering swivel system total energy consumption power E comprises ECU consumed power P _eCU-loss, motor wasted power P _e-motorloss, Hydraulic Pump loss power P _pump-loss, rotary valve loss power P _v-loss.Steering swivel system total energy consumption power E can be expressed as:

$\left\{\begin{array}{c}E=P_{ECU-loss}+P_{E-motorloss}+P_{pump-loss}+P_{v-loss}\\ E=U_A{I}_A+R_A{I}_A+\frac{U_S^2}{R_{elec}}+A_P{r}_P{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_p\&lsqb;\frac{\mathrm{\&rho;}{({\mathrm{qN\&eta;}}_v+A_P{r}_P{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_p)}^2}{8C_{q}NL{(w+\frac{{\mathrm{RK}}_C\mathrm{\&theta;}}{K_C+K_n})}^2}-\frac{\mathrm{\&rho;}{({\mathrm{qN\&eta;}}_v+A_P{r}_P{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_p)}^2}{8C_{q}NL{(w+\frac{{\mathrm{RK}}_C\mathrm{\&theta;}}{K_C+K_n})}^2}\&rsqb;\end{array}\right.---\left(3\right)$

In formula (3), U _afor the available voltage of hydraulic pump drive motor, I _afor Motor Current, R _afor the load resistor of armature current, R _elecfor the resistance on non-armature current, U _sfor power line voltage, L is rotary valve Opening length, and w is rotary valve A/F, K _cfor steering shaft rigidity, K _nfor torque sensor rigidity.

Step 3: choose the coupling variable larger on three main performance critical for the evaluation impacts: stator thickness B, the rotor inertia J of motor and oil pump _m, torque sensor stiffness K _s, Hydraulic Pump rotating speed N, rotary valve rotational angle theta is as the design variable of Electro-Hydraulic Power Steering System;

Step 4: the requirement optimized according to Constrained multiple goal high dimensional nonlinear, with steering feel and steering swivel system energy consumption for optimization aim, take steering sensitivity as system constraints, set up Electro-Hydraulic Power Steering System Model for Multi-Objective Optimization, objective function f (x) that Electro-Hydraulic Power Steering System is optimized is:

$\left\{\begin{array}{c}f\left(x\right)=\frac{k_1}{f\left(x_1\right)}+k_{2}f\left(x_2\right)\\ f\left(x_1\right)=\frac{1}{2{\mathrm{\&pi;\&omega;}}_0}{\&Integral;}_0^{{\mathrm{\&omega;}}_0}|\frac{T_h\left(s\right)}{T_r\left(s\right)}{{|}_{s=j\mathrm{\&omega;}}}^{2}d\mathrm{\&omega;}\\ f\left(x_2\right)=P_{motor-loss}+P_{v-loss}\end{array}\right.---\left(4\right)$

In formula (4): f (x ₁) be road feel function, be information of road surface effective frequency range (0, ω ₀) frequency domain energy aviation value, in process of optimization, get ω ₀=40Hz; F (x ₂) be energy consumption function, be mainly the waste of power of system motor and the waste of power of rotary valve;

The constraint condition of Electro-Hydraulic Power Steering System optimization is:

$f\left(x_3\right)=\frac{1}{2{\mathrm{\&pi;\&omega;}}_0}{\&Integral;}_0^{{\mathrm{\&omega;}}_0}|\frac{{\mathrm{\&omega;}}_r\left(s\right)}{{\mathrm{\&theta;}}_h\left(s\right)}{|}^{2}d\mathrm{\&omega;}---\left(5\right)$

ω in optimizing process ₀=40Hz, for ensureing the reasonableness of steering sensitivity, retraining it, making function meet 0.0008≤f (x ₃the constraint condition of)≤0.0099.

Step 5: adopt the improvement Memetic intelligent algorithm merging cuckoo algorithm to be optimized the mechanical parameter of system, hydraulic system parameters, draw optimum pareto disaggregation, and the optimum compromise choosing designer satisfied is separated.Fig. 3 is the improvement Memetic intelligent algorithm diagram of circuit merging cuckoo algorithm;

As shown in Figure 3, merge the improvement Memetic intelligent algorithm of cuckoo algorithm, the variety of solution can be strengthened, the cuckoo algorithm of convergence speedup speed is implanted in Memetic algorithm, set up the math modeling of the cuckoo algorithm being used for nested type local optimal searching, the Memetic intelligent algorithm improved is a kind of Stochastic Optimization Algorithms combining genetic mechanism and Local Search, and global search strategy adopts the genetic algorithm of floating-point encoding, and local learning strategy adopts cuckoo algorithm.Specific implementation step is as follows:

Step 51: coding.

The feasible solution data sheet of solution space is shown as the floating type string structure data of search volume, namely the various combination of these string structure data constitutes different feasible solutions.

Step 52: the generation of initial population.

Producing initial population is random generation.For the N=0 moment, random generation M feasible solution, the concrete random feasible solution X produced _ifor:

X _i＝rand(0,1)(X _max-X _min)+X _min(6)

Step 53: degree of adaptability calculates.

Step 54: group collaboration.

From current group, choose the individuality of M defect individual (degree of adaptability is high), make them have an opportunity to enter next iteration process, give up the individuality that degree of adaptability is low.Probability and its fitness value of each individual choice are proportional, herein because the total value of fitness value is negative, and should be tending towards minimum value, thus select probability as shown in the formula:

$p_i=\frac{\left|f\left(X_i\right)\right|}{\underset{n=1}{\overset{M}{\&Sigma;}}\left|f\left(X_n\right)\right|}---\left(7\right)$

Individual to initial M of producing, choose arbitrarily two according to the probability of crossover of setting in advance and carry out hybridization computing, or become crossing operation, two that produce colony of new generation new individual.Crossover Operator is herein as follows:

$\begin{array}{c}{P_1}^{nex}=w_1{P}_1+(1-w_1)P_2\\ {P_2}^{nex}=w_2{P}_2+(1-w_2)P_1\end{array}---\left(8\right)$

In formula (8): P ₁, P ₂for two father's individualities of random selecting from population; for the filial generation by producing after crossover operator computing is corresponding new individual; w ₁, w ₂for [0,1] the upper random random number produced.

In the new population that hybridization computing produces, therefrom choose several body according to certain mutation probability, the mutation operator provided by following formula carries out mutation operation:

$V^{new}=\left\{\begin{array}{cc}V+(b_{up}-V){\&lsqb;r(1-t)\&rsqb;}^2,& sign=0\\ V-(V-b_{lb}){\&lsqb;r(1-t)\&rsqb;}^2,& sign=1\end{array}\right.---\left(9\right)$

In formula (9): V is the Mutation parameter chosen; V ^newfor the parameter after variation; Sign gets 0 or 1 at random; b _up, b _lbbe respectively the upper bound and the lower bound of parameter value; R is [0,1] upper random random number produced; T=g _c/ g _mfor the mark of Evolution of Population, wherein, g _cthe algebraically that population works as evolution, g _mit is the maximum evolutionary generation of population.

Step 55: Local Search,

Meme as cultural elementary cell is individual, incorporate cuckoo algorithm in the transmission study and adjustment process of Meme individuality, strengthen the study inverting ability of Meme individuality, all Local Search is carried out after each crossover and mutation, bad individuality is rejected early by the distribution optimizing population, all individualities of each iteration are made all to reach local optimum, thus improve the magnificence of algorithm, the parasitic nest of cuckoo algorithms selection is adopted to all individualities in population, retain the optimum nest of the previous generation, and individual Meme cooperation Local Search is carried out in change nest position, is specially:

To step 54) in all carry out Local Search after each crossover and mutation, cuckoo algorithms are adopted to all individualities in population, using the solution that obtains through genetic algorithm as initial population, calculate degree of adaptability, then Bird's Nest position is upgraded, by following formula:

$K_{g+1,i}=K_{g,i}+\&part;\frac{\mathrm{\&phi;}\&times;u}{|v{|}^{\frac{1}{\mathrm{\&beta;}}}}(K_{g,i}-K_{best})---\left(10\right)$

In formula in (10), K _g,irepresent that i-th Bird's Nest is in the Bird's Nest position in g generation, K _bestfor current optimal solution, for constant;

$\begin{array}{cc}\frac{\mathrm{\&phi;}\&times;u}{|v{|}^{\frac{1}{\mathrm{\&beta;}}}}-u=t^{-\mathrm{\&beta;}}& 1<\mathrm{\&beta;}\&le;3\end{array},---\left(11\right)$

Obey Lay dimension probability distribution, u.v obeys standard normal distribution;

Wherein, $\mathrm{\&phi;}={\left\{\frac{\mathrm{\&Gamma;}(1+\mathrm{\&beta;})sin\left(\frac{\mathrm{\&beta;}}{2}\mathrm{\&pi;}\right)}{\mathrm{\&Gamma;}\left(2^{\frac{\mathrm{\&beta;}-1}{2}}\frac{1+\mathrm{\&beta;}}{2}\mathrm{\&beta;}\right)}\right\}}^{\frac{1}{\mathrm{\&beta;}}}---\left(12\right)$

Relatively relevance grade, retains the new nest of relevance grade higher than previous generation Bird's Nest;

Again according to after the probability dropping partial solution of 5%, random walk is adopted to regenerate the new explanation of equal number:

Ω _g+1,i＝Ω _g,i+rand(0,1)(Ω _g,j-Ω _g,k)(13)

Ω in formula (13) _g,j, Ω _g,kfor two random nests in g generation, make lower generation nest quantitatively be consistent with the previous generation, enter next round optimizing, select new nest after being supplemented, degree of adaptability calculates.Until meet greatest iteration number, complete individual Meme cooperation Local Search;

Step 56: Group Evaluation, optimizes through genetic algorithm, cuckoo algorithm loop iteration, obtains the optimal solution that degree of adaptability is the highest;

Step 57: whether inspection stop condition meets, if meet, carries out next step decoding; No, go to step 53 continuation;

Step 58: decoding, be optimized the optimum pareto disaggregation obtained;

Step 59: designer chooses satisfied optimum compromise and separates.

Step 6, by corresponding for each parameter after optimizing power consumption values with optimize before power consumption values compare, if lower than the power consumption values before optimizing, then think and optimize effectively, choose different initial value and test, the robustness of verification algorithm, avoids locally optimal solution.

The above; be only the utility model preferably detailed description of the invention; but protection domain of the present utility model is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; the change that can expect easily or replacement, all should be encompassed within protection domain of the present utility model.Therefore, protection domain of the present utility model should be as the criterion with the protection domain of claim.

Claims (2)

1. an Electro-Hydraulic Power Steering System, is characterized in that, comprises steering mechanical unit, rotary valve aperture regulon, oil pump regulon and electronic control unit ECU;

Described steering mechanical unit comprises the tierod that the steering handwheel, steering shaft, rack and pinion steering gear and the two ends that connect successively are connected with wheel, and tierod is provided with hydraulic actuating cylinder, and steering shaft is provided with torque sensor;

Described rotary valve aperture regulon comprises connected rotary valve and rotary valve regulates motor, is provided with hydraulic oil-returning pipeline, is provided with hydraulic actuating cylinder chargine line and hydraulic actuating cylinder oil return line between rotary valve and hydraulic actuating cylinder between rotary valve and hydraulic reservoir,

Hydraulic actuating cylinder both sides are provided with hydraulic pressure transducer element;

Described oil pump regulon comprises connected double-acting vane pump and oil pump drive motor; Double-acting vane pump is connected with rotary valve with hydraulic reservoir respectively, and the hydraulic oil exported by hydraulic reservoir is flow to hydraulic actuating cylinder chargine line and hydraulic actuating cylinder oil return line by rotary valve chargine line in rotary valve punishment;

Described electronic control unit ECU is connected with hydraulic pressure transducer element with torque sensor, receives the electric signal that they send, and regulates motor and oil pump drive motor to send control signal to rotary valve.

2. a kind of Electro-Hydraulic Power Steering System according to claim 1, is characterized in that, described electronic control unit ECU is also connected with vehicle-mounted optical pickocff, receives the electric signal sent by vehicle-mounted optical pickocff.