Hydraulic pressure is inertial simulation unit

  • Time:
  • Click:22
  • source:EAGLEBURGER CNC Machining
Summary: Introduced to use hydraulic pump and electro-hydraulic the working principle that scale overflow a powerful person regards the hydraulic pressure that power is absorbed and controls element as unit of inertial and laden simulation and design method. Keyword: Hydraulic pressure of control of inertial imitate scale is inertial imitate, namely in order to be not imitate of inertial hydraulic pressure technology inertial (quality or moment of inertia) the effect. If use the methodological simulation of pure machinery,rotate inertial, the flywheel that is J with an inertia namely is very accurate, but the cost that makes an exact numerical value and activity balance good flywheel is very high, when the flywheel that needs a group of different numerical value especially, not only costly, and assemble and unassemble very complex, become especially when rotate speed is higher, although very small lopsided quality distributings,also can cause insecure consequence. With imitate of hydraulic pressure technology inertial although precision is not tall, but can make successive change, fit different operating mode need, and cost is low, working on the safe side, use machine of imitate of hydraulic pressure technology so inertial it is very significant. The conditional basis that 1 inertial imitate realizes Newton the 2nd law: The relation of force and driving force is: (1a) 　 or (in 1b) type: Fd, Td, driving force and driving moment; υ , N, the speed that the object moves and rotate speed; M, J, the quality of the object and moment of inertia. To type (1) takes Laplace trade, the result is as follows: Fd(s)=ms υ (form discusses only here (the rotational circumstance of 2b) , as to translation its principle is same. Because driving force arises,retarded motion is, adapt so type (2b) is: Type of 　 of Sn(s)=Td(s)/(2 π J)(3) (the block diagram of 3) is shown 1 times like the graph. Just think uses Jp of a small inertia, and the effect that other means will come to achieve J of a big inertia, in the graph the design on the foundation of 1 loses the program of feedback, if pursue,2 are shown. Graph 1 graph 2 　 pursue 2 in, h(s) , the transfer function of feedback link; TAd(s) , add moment of force (or) of feedback moment of force. Pursue according to feedback principle 2 can convey for: 〕 of Sn(s)= 〔 Td(s)-TAd(s) / (the result that 2 π Jp)(4) or 　 of Sn(s)=Td(s)/(2 π JP+H(s))(5) want to realize imitate J, criterion type (3) Ying Heng is equal to type (5) , namely 　 of Jp+H(s)(6) of π of 2 π J=2 solves 　 type (6) , get 　 H(s)=2 π (J-Jp)(7) 　 type (7) is not the sufficient requirement with inertial means inertial imitate to use other namely, and H(s) is one scale link. From the graph TAd=H(s) of 2 knowable and add moment of force.

Sn(s) , skill (7) takes the place of, get TAd(s)=2 π of 　 　 　 namely (J-Jp)sN(s)(8a) 　 or TAd=2 π (this add moment of force can use J-Jp)dn ／ Dt(8b) 　 hydraulic pressure means arises, its principle is shown 3 times like the graph. Graph in 3 graphs, 1 it is the flywheel that inertia is Jp; 2 it is to load pump; 3 it is pressure control equipment. The basis pursues 3, if the machinery on axis of oversight to load chafes pitching moment, namely oversight machinery loss, criterion the angular acceleration of to load axis can express to be: (In 9) type: TB, the moment of hydraulic pressure block that to load pump produces (Q of 　 of 10) 　 , to load pumpage; P, pressure of antrum of high pressure of to load pump; Po, pressure of antrum of low pressure of to load pump, it is suppose 0. To type (9) takes Laplace commutation, the SN(s)= that get 　 [Td(s) - TB(s) ] / (　 of 2 π Jp)(11) consults type (4) , can know to want to control systematic pressure through pressure control equipment only, make TB of hydraulic pressure moment of force is equal to TAd of add moment of force, namely 　 of TB=TAd(12a) of 　 　 　 or TB(s)=TAd(s)(12b) 　 can come true so with the effect with inertial imitate of hydraulic pressure means. 2 hydraulic pressure are inertial the blueprint of simulation unit 4 it is the hydraulic pressure that principle design narrates before applying inertial simulation unit, its job process: Input driving moment Td, make to load pump 2 move quickly, rotate speed sensor signal of 11 collect rotate speed, input controller 4, via operation generation an electric current controls signal, add electro-hydraulic scale overflow a powerful person 3 on, pump of control to load actuating pressure P, the TB of hydraulic pressure moment of force that should make sure to load pump arises only is equal to TAd of add moment of force, achieve the inertial result with Jp imitate J. Graph the condition that 4 　 make TB is equal to TAd is below I of derivation control electric current and K1 of coefficient of controller scale enlarge. Because this inertial simulation unit plans to be used at pump of axial force plunger to control motor system,be in minutely amount to positive and negative 7 times to experiment to concussion, and the frequency of scale overflow a powerful person is wide amount to 6 ～ 10HZ, reason can assume this a powerful person is one scale link. Namely the control pressure of scale overflow a powerful person is: In P=Kpi(13) type: P, pressure of antrum of high pressure of to load pump; I, scale overflow a powerful person inputs electric current; Kp, gain of pressure of scale overflow a powerful person. Solve (8b) , (10) , (12a) , (all 13) type, get control electricity: (14) 　 the output electric current of controller (in 15) type: Kn, coefficient of proportionality of rotate speed sensor; Ka, voltage of scale overflow a powerful person, voltaic enlarge coefficient; K1, the scale enlarge coefficient of controller. By type (14) and (15) can get K1 of coefficient of controller scale enlarge: (The action of this shows controller of 16) 　 is the rotate speed signal of a collect of rotate speed sensor, the differential in classics controller implement in the amplifier that the voltage signal that differential generates to become direct ratio with angular acceleration adds a coefficient to be K1 next, its output reintroduce to arrive electro-hydraulic the voltage of proportioning valve, in voltaic converter, send finally electro-hydraulic in proportioning valve, control to load pump thereby the principle of 4 sees controller of outlet pressure P0 graph 5. Graph 6, graph 7 it is this inertial simulation unit the function of sine wave moment of force that inputting ideal, its cycle is 60/7 second (namely minutely 7 positive and negative to) , amplitude is 343.

35N · M, desire simulative inertia J is taken 1.

225kg · M, emulate through the computer, one group when get emulates a curve. Graph 6 emulation conditions are chief for 1e-5s, what pulsatile part contains in the graph is the angular acceleration that inertial action plays simulation, and a smooth curve is the angular acceleration curve below mechanical inertia action, can see both weaveform is roughly identical. When imitate inertia action, existence is high frequency and pulsatile because,this is electro-hydraulic proportioning valve is contained 2 rank the oscillation that link causes causes. Graph 7 be grow the pace increase a group of when be 1e-4s emulation curves, it is thus clear that pulsatile composition decreases greatly, this basically is the pace grows increase, be equivalent to be being strung together in the system one low connect filter, went to filter of high frequency composition. Graph 5 graphs 6 graphs 73 last words use hydraulic pressure to control the method with systematic inertial and laden imitate, also apply to the system of imitate to load of force of such as bedspring, agglutinant obstruction and aleatoric function force, form idealer trends to measure thereby result implement. CNC Milling CNC Machining