CN103618482B - Method for generating pulses with symmetric trapezoid acceleration and deceleration - Google Patents

Abstract

The invention provides a method for generating pulses with symmetric trapezoid acceleration and deceleration. The method for generating the pulses with symmetric trapezoid acceleration and deceleration comprises the steps that firstly, data are initialized, wherein the initial velocity in the time zero of trapezoid acceleration, the initial velocity at the zero moment of trapezoid deceleration and the number of pulses in the acceleration process or the deceleration process are calculated; secondly, the frequency of pulses in the constant acceleration process and the frequency of pulses in the constant deceleration process are obtained, wherein a pulse frequency value calculated when the constant acceleration process stops serves as a pulse frequency value used when the constant deceleration process begins. Due to the fact that real-time control over each pulse in the operation process of a motor is carried out, the pulses with completely-symmetric acceleration and deceleration can be obtained.

Description

A kind of method producing symmetric trapezium acceleration and deceleration pulse

Technical field

The present invention relates to a kind of method producing symmetric trapezium acceleration and deceleration pulse.

Background technology

Along with the fast development of equipment manufacture, the performance of automation equipment is badly in need of improving, and motor is in automation equipment Typical actuator, the quality of control system runnability is heavily dependent on and controls whether to reach to motor Optimum state.In research motor controls, find that the output pulse of most of controller is being accelerated and in moderating process is being Asymmetric, so the rotating speed causing the motor stop timing can not be reached desired rotating speed, influence whether that motor is in essence Really control the performance of occasion.Traditional algorithm, the controlling curve exported in theory can reach symmetrical effect, can Being to realize but having with theory certain difference within a processor, actual acceleration and deceleration stage output pulse frequency can be higher than reason Stopping the when of the pulse frequency of calculating in opinion, and acceleration and deceleration stage pulse number is unpredictable, easily impact controls essence Degree.

Summary of the invention

Solve the technical problem that

For solving the problem that prior art exists, the present invention proposes a kind of method producing symmetric trapezium acceleration and deceleration pulse.

Technical scheme

Existing algorithm is improved by the present invention, when slowing down, the value of calculation of end of boost is assigned to the value that reduction of speed starts, So can reach the effect that acceleration and deceleration are symmetrical, be conducive to accurately controlling the run location of motor in motor control.

The technical scheme is that

A kind of described method producing symmetric trapezium acceleration and deceleration pulse, it is characterised in that: employing following steps:

Step 1: initialization data:

Step 1.1: use formula g=f₁-β/(2f₁) obtain the initial velocity g, wherein f in trapezoidal acceleration and deceleration zero moment₁ Being the initial velocity value of motor setting, β is motor acceleration；

Step 1.2: utilize formula { [g+ (g+ β t_m)]/2}t_m=m-1 obtains the umber of pulse of accelerator or moderating process M, wherein t_mIt is to accelerate or moderating process total time；

Step 2: enter even accelerator, calculates the frequency of each pulse in even accelerator, and obtains according to step 1 To accelerator umber of pulse determine that even accelerator terminates；

Step 3: after even accelerator terminates, with motor actuating speed constant-speed operation, then enters even moderating process；

Step 4: enter even moderating process, in even moderating process, the pulse frequency calculated when terminating with even accelerator The pulse frequency value that rate value starts as even moderating process；Calculate the frequency of each pulse in even moderating process, and according to The moderating process umber of pulse that step 1 obtains determines that even moderating process terminates.

Beneficial effect

The present invention improves on the basis of existing motor control method, by initial velocity, acceleration, drive Dynamic speed, deceleration, the process of termination these parameters of speed, it can be deduced that the pulse needed in motor operation course Number, and the frequency of each pulse.By the real-time control to pulse each in motor operation course, it is possible to obtain The pulse that acceleration and deceleration are full symmetric.

Accompanying drawing explanation

The flow chart of Fig. 1: the present invention；

Fig. 2: the pulse sequence timings during trapezoidal acceleration and deceleration；

Fig. 3: the moment waveform of asymmetric acceleration and deceleration process；

Fig. 4: the moment waveform of symmetrical acceleration and deceleration process；

Fig. 5: the oscillogram of the actual output in embodiment.

Detailed description of the invention

Below in conjunction with specific embodiment the present invention described:

First the principle of the present invention is given, for the pulse sequence timings during the trapezoidal acceleration and deceleration shown in Fig. 2, when Motor is with initial velocity f₁Start, accelerate with acceleration β, with actuating speed f_sConstant-speed operation, the rate equation of motor Can be expressed as: f=g+ β t, wherein g represents a value less than toggle speed.

T in Fig. 2₁、t₂、t₃、t₄、t₅、……、t_mRepresent the initial time of different frequency pulsing, In each time interval, motor rotates a step angle, so each little trapezoidal area is 1.Two adjacent arteries and veins The time interval Δ t of punching_m=t_m+1–t_m.The then pulse frequency f=1/ Δ t of this moment output_m, this pulse frequency and Ben Shi Between midpoint time pulse frequency identical.

In fig. 2, if t=is Δ t₁When/2, at Δ t₁=1/f₁Time, f=g+ β t can become f₁=g+ Δ t₁/ 2=g+ β/(2f₁), then g=f₁-β/(2f₁)。

T in fig. 2_mM-1 pulses generation was had before moment, so to t_mTrapezoidal integration before moment can obtain {[g+(g+βt_m)]/2}t_m=m-1, obtains t_m={ [g²+2(m-1)β)]^1/2-g}/β, can obtain adjacent two pulses time Between be spaced apart: Δ t_m=t_m+1-t_m={ (g²+2mβ)^1/2-[g²+2(m-1)β)]^1/2}/β, can be every during acceleration and deceleration The frequency of individual pulse is: f_m=1/ Δ t_m={ (g²+2mβ)^1/2+[g²+2(m-1)β)]^1/2}/2。

According to above-mentioned principle, the present embodiment produces the method for symmetric trapezium acceleration and deceleration pulse and uses following steps:

Step 1: initialization data:

Step 1.1: use formula g=f₁-β/(2f₁) obtain the initial velocity g, wherein f in trapezoidal acceleration and deceleration zero moment₁ Being the initial velocity value of motor setting, β is motor acceleration；

Step 1.2: utilize formula { [g+ (g+ β t_m)]/2}t_m=m-1 obtains the umber of pulse of accelerator or moderating process M, wherein t_mIt is to accelerate or moderating process total time；Thus can ensure that and can control motor on different rank The Duan Jinhang automatic switchover method of operation.

Step 2: enter even accelerator, calculates the frequency of each pulse in even accelerator, and obtains according to step 1 To accelerator umber of pulse determine that even accelerator terminates；

Step 3: after even accelerator terminates, with motor actuating speed constant-speed operation, then enters even moderating process；

Step 4: enter even moderating process, in even moderating process, the pulse frequency calculated when terminating with even accelerator The pulse frequency value that rate value starts as even moderating process；Calculate the frequency of each pulse in even moderating process, and according to The moderating process umber of pulse that step 1 obtains determines that even moderating process terminates.

If the pulse frequency that the pulse frequency value calculated when not terminating using even accelerator here starts as even moderating process Rate value, then can cause moderating process to calculate with actuating speed value for initial value, so under certain deceleration pulse, and electricity Pulse frequency when machine stops is bigger, and motor so easily causes certain damage.

In the present embodiment, whole method realizes in FPGA, by the waveform of output it is observed that control output Pulse is symmetrical (shown in Fig. 5), it is achieved that accelerate the most identical with the pulse frequency of deceleration end time, it is achieved with Given umber of pulse arrives the pulse frequency that reach when terminating of slowing down.The symmetrical plus-minus rapid pulse that this method produces Punching, is conducive to controlling pulse frequency when terminating of slowing down, such that motor has the biggest proposing in terms of vibration characteristics High.

Claims (1)

1. the method producing symmetric trapezium acceleration and deceleration pulse, it is characterised in that: employing following steps:

Step 1: initialization data:

Step 1.1: use formula g=f₁-β/(2f₁) obtain the initial velocity g, wherein f in trapezoidal acceleration and deceleration zero moment₁ Being the initial velocity value of motor setting, β is motor acceleration, the time interval Δ t of the first two adjacent pulse₁With motor Initial velocity value f set₁Meet Δ t₁=1/f₁；

Step 1.2: utilize formula { [g+ (g+ β t_m)]/2}t_m=m-1 obtains the umber of pulse of accelerator or moderating process M, wherein t_mBeing to accelerate or moderating process total time, in the time interval of each adjacent pulse, motor revolves Turning a step angle, adjacent pulse time interval is 1 with the trapezoidal area of motor speed composition；

Step 2: enter even accelerator, calculates the frequency of each pulse in even accelerator, and obtains according to step 1 To accelerator umber of pulse determine that even accelerator terminates；

Step 3: after even accelerator terminates, with motor actuating speed constant-speed operation, then enters even moderating process；

Step 4: enter even moderating process, in even moderating process, the pulse frequency calculated when terminating with even accelerator The pulse frequency value that rate value starts as even moderating process；Calculate the frequency of each pulse in even moderating process, and according to The moderating process umber of pulse that step 1 obtains determines that even moderating process terminates.