CN106870181A - Leg legged type robot hydraulic system petrol engine rotation speed servo control method - Google Patents

Abstract

A kind of leg legged type robot hydraulic system petrol engine rotation speed servo control method, (1) calculates the rate of change ec of engine speed error e and speed error；(2) after e and ec is calculated by fuzzy logic, export ratio coefficient increment △ k_pWith integral coefficient increment △ k_i；(3) proportionality coefficient k_p=k_p0+△k_p, integral coefficient k_i=k_i0+△k_i；(4) accelerator open degree S is calculated₁=S_{1_old}+k_p*ec+k_i*e；(5) the accelerator open degree change caused by hydraulic fluid flow rate change turns to S₂=k_Q*△Q；(6) final accelerator open degree S_f=S₁+S₂, accelerator open degree rotated with the form control steering wheel of PWM, and air inflow is controlled by the aperture of throttle line traffic control engine air throttle, finally controls engine speed.The present invention uses feedforward control, and stabilization of speed can be well ensured in the case where flow is mutated；Online modification is carried out to parameter using Fuzzy self- turning, different controls is met and is required, make system that there is good dynamic and static properties.

Description

Leg legged type robot hydraulic system petrol engine rotation speed servo control method

Technical field

The present invention relates to a kind of petrol engine rotation speed servo control method for hydraulic pressure leg legged type robot, belong to vapour The control technology field of oil machine drive hydraulic system principle.

Background technology

, it is necessary to ensure the high dynamic and load capacity of robot in the type of drive of leg legged type robot, therefore its The power source of airborne hydraulic systems should have energy density very high.Although electric drive has the advantages that noise is small, but it is continued a journey The shortcomings of ability, battery charge slow influences it in the application in leg legged type robot field, in hgher efficiency, the body of petrol engine Product is smaller and weight is lower, is easy to implement airborneization of robot energy resource system, therefore hydraulic system driven by the engine is The ideal solution of leg legged type robot drive system.The power of robot hydraulic system is provided by petrol engine, Petrol engine drives Variable plunger pump to rotate, and mechanical energy is converted into the pressure energy of liquid.Robot will stably work, Ask hydraulic system to provide the power of stabilization, it is necessary to adjust petrol engine rotating speed, Variable plunger pump is tieed up under corresponding operating mode Keep steady fixed rotating speed.

Engine controls the application in constant speed of vehicle cruise system and excavator most commonly seen.But patrolled for automobile constant speed The equal volume of engine in boat is larger, is not suitable for hydraulic-driven leg legged type robot, and to the driving of automobile also different from The driving of hydraulic system；The engine for being used for drive hydraulic system principle in excavator is Diesel engine and leg legged type robot The petrol engine for being used, and the operating mode of excavator is also not quite similar with the operating mode of leg legged type robot.Therefore, for being used for The petrol engine of driving leg legged type robot hydraulic system, it is necessary to design a kind of new controller and control method control hair Motivation rotating speed.

Disclosed in Chinese patent literature 201310264575X《Petrol engine driving leg legged type robot hydraulic system is used Control system and control method》, including controller, and the reading hydraulic system pasta being connected with controller oil surface potential Meter, the temperature sensor for reading hydraulic system hydraulic fluid temperature, the pressure sensor for reading hydraulic system oil pressure signal, controller Communicated with master system by CAN interface.

The controller of said system controls the startup of engine and the oil of flame-out and hydraulic system reversal valve by signal Mouth is switched on or switched off, and controller adjusts throttle opening by steering wheel, realizes the constant of engine speed, and can be by passing The working condition of sensor real-time monitoring system, but, it is necessary to change more high-power after the increase of the traffic demand of robot system Engine, original control method can not meet the rotating speed control of high-power engine；And the complexity that tests the speed is, it is necessary to starting The output shaft of machine is transformed, and increased assembly difficulty.

The content of the invention

The present invention is in order to solve the deficiency that existing robot hydraulic system petrol engine control technology is present, there is provided a kind of Make system that there is the leg legged type robot hydraulic system petrol engine rotation speed servo control method of good dynamic and static properties.

Leg legged type robot hydraulic system petrol engine rotation speed servo control method of the present invention, using with feedforward control PI methods (ratio and integration), wherein ratio and integral coefficient comprised the following steps that by fuzzy logic adjust automatically：

(1) according to motor set rotary speed v_refWith actual engine speed v_fed, calculate speed error e and speed error Rate of change ec, wherein e=v_fed-v_ref, ec=(v_fed-v_ref)/T, T are controlling cycle 0.02 second；

(2) after the rate of change ec of above-mentioned speed error e and speed error is calculated by fuzzy logic, export ratio coefficient Increment △ k_pWith integral coefficient increment △ k_i；

(3) it is final, proportionality coefficient k_p=k_p0+△k_p, integral coefficient k_i=k_i0+△k_i；

(4) accelerator open degree S is calculated using increment type PI algorithms₁, S₁=S_{1_old}+k_p*ec+k_i* e, wherein S_{1_old}It is upper one Accelerator open degree in the execution cycle；

(5) the hydraulic fluid flow rate change △ Q in robot kinematics are compensated by feedforward control, by hydraulic fluid flow rate The accelerator open degree change that change causes turns to S₂=k_Q* △ Q, wherein k_Q=27.7min/L；

(6) final accelerator open degree S_f=S₁+S₂, accelerator open degree is with the form control steering wheel rotation of PWM (pulse width modulation) Turn, air inflow is controlled by the aperture of throttle line traffic control engine air throttle, finally control engine speed.

The measurement of the actual engine speed is used and directly uses engine ignition voltage signal U₁The mode of measurement, by R₁And R₂The resistance pressure-dividing network being composed in series carries out step-down treatment, by the voltage U after treatment₂=U₁*R₂/(R₁+R₂)；It The characteristic for unidirectionally being passed through using photoelectrical coupler afterwards converts a signal into direct current signal；Eventually pass comparator and comparison voltage ratio After relatively, output amplitude is the square-wave waveform of 5V, captures the square-wave waveform and calculates actual engine speed v_fed, v_fed= 60*f, wherein f are square wave frequency.

The fuzzy logic is calculated and uses fuzzy supervisory controller, and detailed process is as follows：

Fuzzy supervisory controller is made up of fuzzy device, indistinct logic computer, fuzzy reasoning table and defuzzifier, and its input is to turn The rate of change ec of fast error e and speed error, fuzzy device using membership function by e and ec change into fuzzy variable NB, NS, The membership function expression formula of ZO, PS and PB, e and ec is as follows, and wherein x is n=150 in the membership function of e or ec, e, ec's N=60 in membership function：

Indistinct logic computer utilizes △ k afterwards_pFuzzy reasoning table and △ k_iFuzzy reasoning table will be input into fuzzy set mapping To output fuzzy set；Wherein：

△k_pFuzzy reasoning table it is as follows：

△k_iFuzzy reasoning table it is as follows：

Last defuzzifier calculates export ratio coefficient and increases using the method for the average ambiguity solution of membership function and center Amount △ k_pWith integral coefficient increment △ k_i；△k_pWith △ k_iMembership function expression formula it is as follows, wherein y be △ k_pOr △ k_i, △ k_pMembership function in n=1, △ k_iMembership function in n=0.1：

The present invention can be more convenient accurate real-time detection engine speed by the tachometer circuit after improvement, and then The output speed of petrol engine is controlled, makes the stabilization of speed of maintenance Variable plunger pump on the corresponding rotating speed of different operating modes, be Hydraulic system under different conditions provides the energy output of stabilization；Rotating speed control is using the PI with feedforward control (Proportional-Integral, proportional, integral) method, wherein ratio and integral coefficient pass through fuzzy logic adjust automatically, The on-line tuning of coefficient can be realized, makes system that there is good dynamic and static properties；Feedforward control can be transported to robot Flow mutation during row is compensated, and reduces engine speed fluctuations, it is ensured that what Variable plunger pump can be stablized is system Flow is provided.

The present invention has several lower features：

1. the tachometer circuit for using, tests the speed conveniently, reduces Automatic manual transmission difficulty；

2., using the control method based on feedforward, stabilization of speed can well be ensured in the case where flow is mutated；

3. online modification is carried out to PI controller parameters using the method for Fuzzy self- turning, meets different control requirements, Make control system that there is good dynamic and static properties.

Brief description of the drawings

Fig. 1 is the engine tachometer circuit schematic diagram used in the present invention.

Fig. 2 is control method theory diagram of the invention.

Fig. 3 is e and ec triangle membership function schematic diagrames.

Fig. 4 is △ k_pWith △ k_iTriangle membership function schematic diagram.

Specific embodiment

Leg legged type robot hydraulic system petrol engine rotation speed servo control method of the present invention, the tachometer circuit of use is such as Shown in Fig. 1, by the way of directly engine ignition signal measurement engine speed is used.Because initial signal peak-to-peak value is about 100V, it is therefore desirable to by R₁And R₂The resistance pressure-dividing network being composed in series carries out step-down treatment, by the voltage U after treatment₂= U₁*R₂/(R₁+R₂)；Afterwards by photoelectrical coupler, direct current signal is converted a signal into using its characteristic for unidirectionally passing through；Finally After comparing with comparison voltage by comparator LM393, output amplitude is the square-wave waveform of 5V, is captured by single-chip microcomputer trapping module And rotating speed is calculated, computing formula is v_fed=60*f, wherein f are the square wave frequency that single-chip microcomputer capture square wave is obtained.

Engine speed, i.e. Variable plunger pump rotating speed control using with feedforward control PI methods, wherein ratio and Integral coefficient passes through fuzzy logic adjust automatically.

Referring to Fig. 2, the specific step of leg legged type robot hydraulic system petrol engine rotation speed servo control method of the present invention It is rapid as follows：

1) according to motor set rotary speed v_refThe actual engine speed v measured with tachometer circuit shown in Fig. 1_fed, calculate Go out the rate of change ec of speed error e and speed error, wherein ec=v_fed-v_ref, ec=(v_fed-v_ref)/T, T are controlling cycle 0.02s (second)；

2) after the rate of change ec of above-mentioned speed error e and speed error is calculated by fuzzy supervisory controller, output ratio Example coefficient increment △ k_pWith integral coefficient increment △ k_i；

3) final PI controllers (pi controller) parameter is：Proportionality coefficient k_p=k_p0+△k_p, integral coefficient k_i =k_i0+△k_i；

4)S₁It is the accelerator open degree calculated by PI controllers, increment type PI algorithms, wherein S is employed during calculating₁= S_{1_old}+k_p*ec+k_i* e, wherein S_{1_old}It is the accelerator open degree calculated by PI controllers in the upper execution cycle；

5) the changes in flow rate △ Q in robot kinematics are compensated by feedforward controller, are caused by changes in flow rate Accelerator open degree change turns to S₂=k_Q* △ Q, wherein k_Q=27.7min/L；

6) final accelerator open degree S_f=S₁+S₂, accelerator open degree is rotated with the form control steering wheel of PWM, by throttle line traffic control The aperture of engine air throttle controls air inflow, finally controls engine speed.

Wherein, fuzzy control is specifically expressed as follows：

Fuzzy supervisory controller is made up of fuzzy device, indistinct logic computer, fuzzy reasoning table and defuzzifier, and its input is to turn E and ec are changed into mould by the rate of change ec of fast error e and speed error, fuzzy device using the triangle membership function shown in Fig. 3 Paste variable NB, NS, ZO, PS and PB；The membership function expression formula of e and ec is as follows, and wherein x is the membership function of e or ec, e N=60 in the membership function of middle n=150, ec：

Indistinct logic computer utilizes △ k afterwards_pFuzzy reasoning table and △ k_iFuzzy reasoning table will be input into fuzzy set mapping To output fuzzy set；Wherein, △ k_pFuzzy reasoning table it is as follows：

△k_iFuzzy reasoning table it is as follows：

Last defuzzifier is calculated defeated using the method for the average ambiguity solution of the triangle membership function shown in Fig. 4 and center Go out proportionality coefficient increment △ k_pWith integral coefficient increment △ k_i。△k_pWith △ k_iMembership function expression formula it is as follows, wherein y is △k_pOr △ k_i, △ k_pMembership function in n=1, △ k_iMembership function in n=0.1：

Parameter is as follows in Fig. 3 and Fig. 4：Ω_e=150rpm, Ω_ec=60rpm/s, kp₀=180, ki₀=15, △ k_p,max= 3, △ k_i,max=0.3.

Claims (3)

1. a kind of leg legged type robot hydraulic system petrol engine rotation speed servo control method, it is characterized in that, including following step Suddenly：

(1) according to motor set rotary speed v_refWith actual engine speed v_fed, calculate the change of speed error e and speed error Rate ec, wherein e=v_fed-v_ref, ec=(v_fed-v_ref)/T, T are controlling cycle 0.02 second；

(2) after the rate of change ec of above-mentioned speed error e and speed error is calculated by fuzzy logic, export ratio coefficient increment △k_pWith integral coefficient increment △ k_i；

(3) it is final, proportionality coefficient k_p=k_p0+△k_p, integral coefficient k_i=k_i0+△k_i；

(4) accelerator open degree S is calculated using increment type PI algorithms₁, S₁=S_{1_old}+k_p*ec+k_i* e, wherein S_{1_old}It is upper one execution Accelerator open degree in cycle；

(5) the hydraulic fluid flow rate change △ Q in robot kinematics are compensated by feedforward control, are changed by hydraulic fluid flow rate The accelerator open degree change for causing turns to S₂=k_Q* △ Q, wherein k_Q=27.7min/L；

(6) final accelerator open degree S_f=S₁+S₂, accelerator open degree rotates with the form control steering wheel of PWM, by controlling air inflow, most Engine speed is controlled eventually.

2. leg legged type robot hydraulic system petrol engine rotation speed servo control method according to claim 1, it is special Levying is, the measurement of the actual engine speed is used and directly uses engine ignition voltage signal U₁The mode of measurement, by R₁With R₂The resistance pressure-dividing network being composed in series carries out step-down treatment, by the voltage U after treatment₂=U₁*R₂/(R₁+R₂)；It is sharp afterwards The characteristic unidirectionally passed through with photoelectrical coupler converts a signal into direct current signal；Eventually pass comparator and comparison voltage ratio than Afterwards, output amplitude is the square-wave waveform of 5V, captures the square-wave waveform and calculates actual engine speed v_fed, v_fed=60*f, Wherein f is square wave frequency.

3. leg legged type robot hydraulic system petrol engine rotation speed servo control method according to claim 1, it is special Levying is, the fuzzy logic is calculated and uses fuzzy supervisory controller, and detailed process is as follows：

Fuzzy supervisory controller is made up of fuzzy device, indistinct logic computer, fuzzy reasoning table and defuzzifier, and its input is missed for rotating speed E and ec are changed into fuzzy variable NB, NS, ZO, PS by the rate of change ec of difference e and speed error, fuzzy device using membership function And the membership function expression formula of PB, e and ec is as follows, wherein x is n=150 in the membership function of e or ec, e, and ec's is subordinate to N=60 in degree function：

$\mathrm{\&mu;}NB\left(x\right)=\left\{\begin{array}{c}1,x\&le;-2n\\ -\frac{1}{n}x-1,-2n<x\&le;-n\end{array}\right.,\mathrm{\&mu;}NS\left(x\right)=\left\{\begin{array}{c}\frac{1}{n}x+2,-2n<x\&le;-n\\ -\frac{1}{n}x,-n<x\&le;0\end{array}\right.,$

$\mathrm{\&mu;}ZO\left(x\right)=\left\{\begin{array}{c}\frac{1}{n}x+1,-n<x\&le;0\\ -\frac{1}{n}x+1,0<x\&le;n\end{array}\right.,\mathrm{\&mu;}PS\left(x\right)=\left\{\begin{array}{c}\frac{1}{n}x,0<x\&le;n\\ -\frac{1}{n}x+2,n<x\&le;2n\end{array}\right.,$

$\mathrm{\&mu;}PB\left(x\right)=\left\{\begin{array}{c}\frac{1}{n}x-1,n<x\&le;2n\\ 1,x\&GreaterEqual;2n\end{array}\right.;$

Indistinct logic computer utilizes △ k afterwards_pFuzzy reasoning table and △ k_iFuzzy reasoning table will be input into fuzzy set be mapped to it is defeated Go out fuzzy set；Wherein：

△k_pFuzzy reasoning table it is as follows：

△k_iFuzzy reasoning table it is as follows：

Last defuzzifier calculates export ratio coefficient increment △ k using the method for the average ambiguity solution of membership function and center_p With integral coefficient increment △ k_i；△k_pWith △ k_iMembership function expression formula it is as follows, wherein y be △ k_pOr △ k_i, △ k_pPerson in servitude N=1, △ k in category degree function_iMembership function in n=0.1：

$\mathrm{\&mu;}NB\left(y\right)=\left\{\begin{array}{c}1,y\&le;-3n\\ -\frac{1}{n}y-2,-3n<y\&le;-2n\end{array}\right.,\mathrm{\&mu;}NM\left(y\right)=\left\{\begin{array}{c}\frac{1}{n}y+3,-3n<y\&le;-2n\\ -\frac{1}{n}y-1,-2n<y\&le;-n\end{array}\right.,$

$\mathrm{\&mu;}NS\left(y\right)=\left\{\begin{array}{c}\frac{1}{n}y+2,-2n<y\&le;-n\\ -\frac{1}{n}y,-n<y\&le;0\end{array}\right.,\mathrm{\&mu;}ZO\left(y\right)=\left\{\begin{array}{c}\frac{1}{n}y+1,-n<y\&le;0\\ -\frac{1}{n}y+1,0<y\&le;n\end{array}\right.,$

$\mathrm{\&mu;}PS\left(y\right)=\left\{\begin{array}{c}\frac{1}{n}y,0<y\&le;n\\ -\frac{1}{n}y+2,n<y\&le;2n\end{array}\right.,\mathrm{\&mu;}PM\left(y\right)=\left\{\begin{array}{c}\frac{1}{n}y-1,n<y\&le;2n\\ -\frac{1}{n}y+3,2n<y\&le;3n\end{array}\right.,$

$\mathrm{\&mu;}PB\left(y\right)=\left\{\begin{array}{c}\frac{1}{n}y-2,2n<y\&le;3n\\ 1,y\&GreaterEqual;3n\end{array}\right..$