CN1293700C

CN1293700C - Direct measuring and controlling method with DC motor

Info

Publication number: CN1293700C
Application number: CNB2004100986267A
Authority: CN
Inventors: 张建华
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-12-14
Filing date: 2004-12-14
Publication date: 2007-01-03
Anticipated expiration: 2024-12-14
Also published as: CN1614871A

Abstract

The present invention relates to a direct measuring and controlling method with a DC motor, which is characterized in that a pulse signal corresponding to the physical positions of an electric brush and a stator magnetic pole is directly extracted from an armature current of a DC motor through utilizing a circuit; the width of the pulse signal is W, and the pulse counting is N. According to N and W, the rotary angle of each rotor, the number of rotating turns, and the rotating speed of a DC motor are calculated, and the resistant states and the resistance force are judged; consequently, the device containing the DC motor is directly controlled. The method of the present invention has the advantage that the controller can be designed and manufactured without a sensor; when the device containing the DC motor is controlled; the operation is simple, accurate and practical.

Description

The direct measurement and control method that contains DC electric machine

Technical field

The present invention relates to the measurement control method of electromechanical equipment, more detail is a kind of direct measurement and control method that contains DC electric machine, be used to manufacture and design the controller that contains DC electric machine.

Background technology

Direct current machine is widely used in the various activities in production such as industry, agricultural, transportation.The control of DC device can be implemented control to various electromechanical equipments, emulated robot, manipulator etc. with direct current machine and the device that is connected, to realize intended function.To control the device that contains direct current machine, at first will know their speed, stroke, position.Existing technology normally adopts transducers such as Hall element, photoelectric sensor, tachogenerator, travel switch to be achieved.Fig. 1 schematically shows the measurement control method that contains DC electric machine in the prior art.As seen from Figure 1, the device that contains direct current machine need pass through various signal feedback that transducers such as Hall element, photoelectric sensor, tachogenerator, travel switch measure to controller, sends instruction by controller then and controls the device that contains direct current machine.Method of the prior art is used for controlling the device that contains direct current machine, and its weak point is, makes controller and apparatus structure complexity, cost height, in addition, adopts transducer, must also can introduce self error of transducer.

At present, also has a kind of measurement control method that contains DC electric machine in the prior art, it is by measuring armature supply, according to the size of armature supply judge be subjected to resistance the size or be not obstructed, implement control with this, the weak point of this method is, because the dispersiveness of the parameter of electric machine, the threshold value of judgement is difficult for determining; When electric current is interfered, easily erroneous judgement; Angle of rotor be can not measure, the number of turns, rotating speed rotated.

Summary of the invention

The object of the present invention is to provide a kind of direct measurement and control method that contains DC electric machine, the inventive method is handled through accurate by the parameter signal that directly extracts with circuit in the direct current machine armature supply, can judge its operation conditions intuitively, accurately.Realize that the object of the invention technical characterictic is, rotor DC machine is in rotation process, and during the physical centre line of every adjacent pole N level through stator and the S utmost point, armature winding all will commutate by brush and commutator.By long-term observation, experiment and research, sum up following rule: described armature winding is in when commutation, and the armature supply of direct current machine is the corresponding pulsation of physical location of appearance and brush, magnetic pole of the stator always.The origin cause of formation of this pulsation has three aspects, and the firstth, cause by the commutation of brush; The secondth, non-vanishing the causing of commutation moment magnetic flux density; The 3rd is that the periodicity of the spatial distribution of motor gas-gap magnetic flux causes.Based on this, the present invention determines the various operational factors of direct current machine by the following stated method, and implements control by drive unit to containing DC electric machine according to these parameters.

The method of the invention, concrete steps are:

1. directly use sample resistance and signal processing unit, in the armature electric current with brush, the corresponding fluctuating signal of magnetic pole of the stator physical location, be transformed into the digital pulse signal that pulse duration is W;

2. calculation control unit is N to this digital pulse signal counting, and N and W are carried out computing, obtains rotational angle theta, rotation number of turns m, the rotation speed n of rotor, and judges that rotor is subjected to the size of resistance and the state that is obstructed;

3. calculation control unit is sent control signal according to N, W, θ, m, n, by driver element, implements control to containing DC electric machine.

The step 2 of said method of the present invention is to obtain the rotational angle theta of DC motor rotor according to following computing formula (1), rotates number of turns m, rotation speed n, and judge whether direct current machine is the state of being obstructed, thus implement control.

θ = \frac{2 πN}{p} \infty N

m = \frac{N}{p} \infty N - - - (1)

n = \frac{1}{Wp} \infty \frac{1}{W}

W＞setting threshold, direct current machine are judged as and are obstructed.

In addition, according to the following relational expression (2) of dc motor speed n and moment T, can calculate the size of direct current machine moment.Encouraging direct current machine with permanent magnetism or it is that example has:

n = \frac{Ua}{C_{E} Φ} - \frac{Ra}{C_{E} C_{T} Φ_{2}} T - - - (2)

In the formula (2): φ is an air-gap flux, and Ua is an armature voltage, and Ra is an armature resistance, C _E, C _TBe structural constant.

According to above-mentioned formula (2) and (1) as can be known, when T increased, n reduced, and W increases, explanation thus, and pulse duration W can rise with moment T is dull, can judge the size of moment or power in view of the above according to the size of W.

Comprise two parts circuit in the step 1 of said method:

1. be connected on the sample resistance in the armature circuit, its effect is that armature supply is transformed into voltage sampling signal.

2. be connected the signal processing unit between sample resistance and the calculation control unit, its effect is that voltage sampling signal is transformed into digital pulse signal.Described signal processing unit can be realized as the element circuit combination by amplifier of the prior art, filter, comparator, amplitude limiter, frequency divider, frequency multiplier, analog to digital converter, counter, logical circuit.These circuit also can partly be included in the single-chip microcomputer.

Calculation control unit in the step 2 of said method can be made of single-chip microcomputer, computer, counter, timer, programmable logic device, is connected between signal processing unit and the driver element, and it can receive external command.

Compare with the direct measurement and control method that contains DC electric machine of the prior art, the invention has the beneficial effects as follows:

1. without transducer, simplified structure reduces cost, and no transducer is introduced error;

2. because the present invention mainly adopts digital technology, the setting threshold scope of application strengthens, and antijamming capability improves;

3. can calculate angle of rotor θ, rotate number of turns m, rotation speed n, and can judge the size that is subjected to resistance.

Description of drawings

Fig. 1 is for containing the measurement control method schematic diagram of DC electric machine in the prior art.

Fig. 2 is the direct measurement and control method schematic diagram that contains DC electric machine of the present invention.

Fig. 3 is an embodiment of the invention program flow diagram.

Fig. 4 is according to the electric glass lifting controller example structure block diagram of the inventive method design.

Embodiment

Now introduce the direct measurement and control method of DC electric machine and the electric glass lifting controller that designs according to the inventive method of containing of the present invention in conjunction with Figure of description 2-4.

1. extract in the armature electric current and brush, the corresponding electric fluctuating signal of magnetic pole of the stator physical location by sample resistance, and electric fluctuating signal is transformed into the digital pulse signal that pulse duration is W by signal processing unit;

(2) calculation control unit is N to this digital pulse signal counting, and N and W are carried out computing, calculates rotational angle theta, rotation number of turns m, the rotation speed n of rotor, and judges that rotor is subjected to the size of resistance and the state that is obstructed;

(3) calculation control unit is sent control signal according to N, W, θ, m, n, by driver element, implements control to containing DC electric machine.

For further specifying the method for the invention, be that example is illustrated with the electric glass lifting controller.This controller can not need transducer, and the control common DC motor is realized a touch lifting and prevented to clamp function.

Below in conjunction with Fig. 3 and Fig. 4, describe in further detail of the present invention.The operating procedure of electric glass lifting controller is shown in detail in the accompanying drawing 3.

Fig. 4 illustrates principle and the block diagram that electric glass lifting controller of the present invention is implemented control.

1. power unit: U1 forms power circuit with capacitor C 1, C2, C3, and DC12V is reduced to DC5V, as the power supply of single-chip microcomputer U2 and signal processing circuit U3.

2. motor-driven part: single-chip microcomputer U2 sends control signal, drives relay K 1, K2 by triode Q1, Q2, the main story of control electric glass lifter direct current machine M, reverses and stops.

3. signal processing: the direct current machine armature current signal as shown in Figure 2, through sample resistance R1, becomes voltage signal; By behind the signal processing unit U3, become digital pulse signal, as shown in Figure 2 again.

4. instruction importation: the lifting instruction is a significant level when meeting DC12V, is divided into Transistor-Transistor Logic level through divider resistance R4, R5, R6, R7, filter burr with electric capacity C4, C5 after, be input among the single-chip microcomputer U2.

5. single chip part: single-chip microcomputer U2 to the climb command handling process as shown in Figure 3.Receive rise instruction after, drive motors M just changes, glass rises.In the glass uphill process, as W＞setting threshold, illustrate that then direct current machine is obstructed, according to step-by-step counting N, calculate rotor and rotate the number of turns, thereby obtain glass position.If the position, illustrates then that this is obstructed is that single-chip microcomputer U2 sends instruction, stops motor rotation because glass reaches the top at the top, glass stops to rise, and the protection motor does not generate heat; If the position, illustrates then that this is obstructed is that single-chip microcomputer U2 sends signal because glass is clamped foreign matter in the centre, glass descends, the distance of decline motor turning collar number, and perhaps step-by-step counting is stipulated, preventing to clamp the size of power sense, also is to be determined by pulsewidth W, prevents the function of clamping thereby reach.The processing of decline instruction and the processing of climb command are similar.

Among the whole embodiment, need not transducer, directly judge whether to clamp foreign matter and still arrive the top according to digit pulse counting N and pulsewidth width W, and the calculation control dropping distance.

According to the description of electric glass lifting controller, can design the many different distortion and the substitute of electric glass lifting controller of the present invention.Such as, computer control unit can be selected Z8,51, PIC, EM, Motorola Series chip for use, also can select other chip with CPU, I/O, RAM, EPROM, Flash or other similar functions and assemblies for use; Signal processing unit can be selected the chip and the assembly of various operational amplifiers, filter, comparator, frequency divider, frequency multiplier, calculator, amplitude limiter, analog to digital converter, Digital Logical Circuits or other similar functions for use.

Can also the signal that measure be used for showing in the present invention, make to monitor purposes such as indication or warning.

Should be appreciated that to the invention is not restricted to the above embodiment,,, all do not break away from the protection range of design of the present invention and the application's claims various changes and the improvement that the inventive method institute structure is established for the professional in present technique field.

Claims

1. measurement control method that contains DC electric machine is characterized in that:

(1) directly use sample resistance and signal processing unit, in the armature electric current with brush, the corresponding fluctuating signal of magnetic pole of the stator physical location, be transformed into the digital pulse signal that pulse duration is W;

(2) calculation control unit for N, is carried out computing to N and W to this digital pulse signal counting, obtains the rotational angle theta of rotor, rotates number of turns m, and rotation speed n judges that rotor is subjected to the size of resistance and the state that is obstructed;

2. method according to claim 1 is characterized in that described sample resistance is connected on armature circuit, and armature supply is become voltage sampling signal.

3. method according to claim 1, it is characterized in that, described signal processing unit by amplifier, filter, comparator, amplitude limiter, frequency divider, frequency multiplier, counter, digital to analog converter, logical circuit is all or part of combines, be connected the circuit between sample resistance and the calculation control unit, voltage sampling signal is transformed into digital pulse signal.

4. method according to claim 1, it is characterized in that, partial pulse signal in the described digital pulse signal is corresponding with the physical location of brush, magnetic pole of the stator, its pulse duration W, be inversely proportional to rotor speed n, W is with being added by the resistance monotone increasing, and it counts N, is proportional to rotor rotation number of turns m or rotational angle theta.

5. method according to claim 1 is characterized in that described calculation control unit is made up of single-chip microcomputer, computer, counter, timer, trigger, can accept external command.

6. method according to claim 1 is characterized in that, when pulse duration W＞setting threshold, is judged as and is obstructed, and sends control signal in view of the above.

7. method according to claim 1, it is characterized in that, pulse counter N is multiplied by a scale factor, as the rotor number of turns, angle of rotor and contain the stroke, corner of DC electric machine and as the basis for estimation that reaches desired location, send control signal in view of the above.

8. according to the described method of claim 1, it is characterized in that, multiply by a scale factor, as direct current machine itself or contain the speed or the rotating speed of DC electric machine, send control signal in view of the above with the inverse of pulse duration W.