CN102380569A - Control method for setting constant speed, constant strain and variable strain process pressing curve - Google Patents

Abstract

The invention relates to a control method for setting a constant speed, constant strain and variable strain process pressing curve. The control method is used for a hydraulic machine, wherein a linear displacement sensor is arranged on a sliding block; and a position input module which is correspondingly connected with the linear displacement sensor is arranged on a programmable logical controller (PLC). The control method comprises the following steps of: initializing a program; reading a position signal, input by the linear displacement sensor, of the sliding block; calculating the running speed of the sliding block according to the read position signal; comparing the calculated actual running speed with a preset speed; if the calculated actual running speed is equal to the preset speed, entering a last step; if the calculated actual running speed is not equal to the preset speed, entering a next step; substituting the actual running speed into a proportion integration differentiation (PID) controller for calculating; and respectively controlling the start of proportional servo valves arranged on the four corners of the sliding block by using the PLC according to a calculation result of the PID.

Description

Set constant speedpump, constant strain and the allergic effect skill compaction curve control method of exchanging work

Technical field

The present invention relates to a kind of control system of hydraulic press, particularly relate to a kind of can be according to setting constant speedpump, constant strain and allergic effect that the velocity of displacement curve point that sets the simulates conic section skill compaction curve control method of exchanging work.

Background technology

Develop rapidly along with forging industry; Special material, accurate forging and pressing require also increasingly high to the technical performance of forcing press; Be directed to the requirement of press to constant speedpump, constant strain, allergic effect transformation system speed in the pressing process, the compacting initialization system of relevant press strain rate arises at the historic moment.

Summary of the invention

The present invention is for solving the technical problem that exists in the known technology, and a kind of setting constant speedpump, constant strain and allergic effect that can make the user set press constant speedpump, constant strain and allergic effect transformation system curve simply and easily compaction curve control method of planting of exchanging work is provided.

The present invention for the technical scheme that solves the technical problem that exists in the known technology and take is: a kind of setting constant speedpump, constant strain and the allergic effect skill compaction curve control method of exchanging work; Be to be used for slide block to be provided with linear displacement transducer; PLC is provided with on the hydraulic press with the position input module of the corresponding connection of said linear displacement transducer, comprises the steps:

1) program initialization;

2) read the position signalling of the slide block that linear displacement transducer imports;

3) calculate the speed of service of slide block according to the position signalling that read;

4) the actual motion speed that calculates is compared with the speed of having set, if equate to get into the 6th step, otherwise, get into next step;

5) bring actual motion speed the computing of into PID controller;

6) PLC controls the unlatching of the proportional servo valve on four angles that are arranged on slide block respectively according to PID controller operation result.

The described speed of service of calculating slide block according to the position signalling that read of step 2 is, the displacement of V=M/T M in the T time range, taking place, and T is a sampling time interval.

Setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work; The advantage and the good effect that have are: can simulate conic section according to the velocity of displacement curve point that sets; Better meet workpiece theoretical molding curve in pressing process; Make the user set press constant speedpump, constant strain and allergic effect transformation system curve simply and easily, improve the forging equipment quality, reduce its manufacturing cost, improve the international competitiveness of domestic forging equipment manufacture greatly.

Description of drawings

Fig. 1 is a method flow diagram of the present invention;

Fig. 2 is a PID control principle block diagram;

Fig. 3 is that the actual speed and the setting speed curve of constant speedpump followed figure;

Fig. 4 is that actual speed and the setting speed curve that allergic effect becomes followed figure.

The specific embodiment

For further understanding summary of the invention of the present invention, characteristics and effect, enumerate following examples now, and conjunction with figs. to specify setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work following:

Setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work is to be used for slide block to be provided with linear displacement transducer, and PLC is provided with on the hydraulic press with the position input module of the corresponding connection of linear displacement transducer.Simultaneously on slider of hydraulic press, be respectively arranged with the proportional servo valve that is used for the adjusting slider speed of service, described proportional servo valve is connected with the output control module of PLC.

Setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work can be provided with constant speedpump, constant strain rate, allergic effect variable Rate on the touch screen human-computer interface of hydraulic press.Automatic adjusting through closed-loop control system makes the hydraulic fluid press slide go motion according to the rate curve of setting.Workpiece is realized deformation under the effect of the rate curve of setting.Quality behind the Workpiece shaping is promoted greatly.

As shown in Figure 1, setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work comprises the steps:

1) program initialization;

2) read the position signalling of the slide block that the linear displacement transducer that is separately positioned on the slide block imports;

3) calculate the speed of service of slide block according to the position signalling that read;

The described speed of service according to the position signalling calculating slide block that is read is that V=M/T M is that T is a sampling time interval in the displacement of T time range inner slide generation.

4) the actual motion speed that calculates is compared with the speed of having set, if equate to get into the 6th step, otherwise, get into next step;

5) bring actual motion speed and setting speed the computing of into PID controller;

In industry spot control system, control law is PID control the most widely.Conventional PID controller principle block diagram is as shown in Figure 3.By the PID controller ^[29]Form with controlled device, PID controller control object is realized objective function.

The PID controller is a kind of linear controller; It constitutes control deviation e (t)=r (t)-c (t) according to set-point r (t) and real output value c (t); Ratio (P), integration (I) and the differential (D) of deviation are constituted controlled quentity controlled variable through linear combination, controlled device is controlled, his control law is:

$u\left(t\right)=K_p[e\left(t\right)+\frac{1}{T_I}{\∫}_0^{t}e\left(t\right)\mathrm{dt}+T_D\frac{\mathrm{de}\left(t\right)}{\mathrm{dt}}]---(1-1)$

Discrete PI D (proportional-integral-differential) controller control algolithm often obtains by the analog pid control algolithm is discrete.Through formula (1-1) is carried out discretization, obtain the digital PID algorithm

$u\left(k\right)=k_P(e\left(k\right)+\frac{T_S}{T_I}\underset{i}{\overset{k}{\mathrm{\Σ}}}e\left(i\right)+\frac{T_D}{T_S}[e\left(k\right)-e(k-1)\left]\right)+u_0---(1-2)$

The increment formula of digital PID algorithm is:

$u\left(k\right)=k_P\left\{\right[e\left(k\right)-e(k-1)]+\frac{T_S}{T_I}e\left(k\right)+\frac{T_D}{T_S}[e\left(k\right)-2e(k-1)+e(k-2)\left]\right\}+u(k-1)---(1-3)$

Realize through program according to above formula (1-3).

6) PLC is according to PID controller operation result, and control is arranged on the unlatching of the proportional servo valve of slide block respectively.

Follow figure like Fig. 3, constant speedpump shown in Figure 4, actual speed and the setting speed curve that allergic effect becomes; Can see that represented actual speed of jaggies among the figure and the represented setting speed of heavy line among the figure are very approaching, and the represented setting speed of the heavy line among the figure adopts setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work to draw.So setting constant speedpump of the present invention, constant strain and the allergic effect skill compaction curve control method of exchanging work makes the user set press constant speedpump, constant strain and allergic effect transformation system curve simply and easily, raising forging equipment quality, reduce its manufacturing cost.

Claims (2)

1. set constant speedpump, constant strain and the allergic effect skill compaction curve control method of exchanging work for one kind; Be to be used for slide block to be provided with linear displacement transducer; PLC is provided with on the hydraulic press with the position input module of the corresponding connection of said linear displacement transducer; It is characterized in that, comprise the steps:

1) program initialization;

2) read the position signalling of the slide block that linear displacement transducer imports;

3) calculate the speed of service of slide block according to the position signalling that read;

4) the actual motion speed that calculates is compared with the speed of having set, if equate to get into the 6th step, otherwise, get into next step;

5) bring actual motion speed the computing of into PID controller;

6) PLC controls the unlatching of the proportional servo valve on four angles that are arranged on slide block respectively according to PID controller operation result.

2. setting constant speedpump according to claim 1, constant strain and the allergic effect skill compaction curve control method of exchanging work; It is characterized in that; The described speed of service according to the position signalling calculating slide block that is read of step 2 is; The displacement of V=M/T M in the T time range, taking place, T is a sampling time interval.

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