CN104444671B - Elevator speed measurement method and system and elevator low-speed starting control method - Google Patents

Abstract

The invention discloses an elevator speed measurement method and system and an elevator low-speed starting control method. The speed measurement method comprises the steps of (1) sampling analog signals output by a sin-cos encoder at intervals of the preset time delta t, and using the current sampling time as the sampling time t, wherein the analog signals include the signal A and the signal B; (2) reading a code value y＜A,t＞ of the signal A at the sampling time t and a code value y＜B,t＞ of the signal B at the sampling time t, and calculating the electrical angle theta t at the sampling time t according to the code value y＜A,t＞ and the code value y＜B,t＞; (3) according to the electrical angle theta t at the sampling time t and the electrical angle theta (t-1) at the previous sampling time (t-1), working out the electrical angle increment delta theta t corresponding to the sampling time t within the preset time delta t, and according to the electrical angle increment delta theta t and the preset time delta t, obtaining the speed Vt at the current sampling time through calculation; (4) if speed measurement is not finished, executing the step (1), and continuing speed measurement at the next sampling time. According to the speed measurement method, the speed measurement precision is greatly improved, the time delay is small, convergence is fast, and the speed measurement method is applicable to low speed measurement.

Description

Elevator speed-measuring method, system and elevator low rate start control method

Technical field

The present invention relates to control technical field, particularly relate to a kind of elevator speed-measuring method, system and elevator low Speed starts control method.

Background technology

In prior art, the real time speed measuring of elevator is usually and uses encoder to detect angular displacement or straight-line displacement It is converted into output of pulse signal, the change of elevator position can be calculated according to the pulse number sampled, enter And obtain the speed of elevator, but it is exactly that precision is the highest that this method exists a defect.

With reference to Fig. 1, in step-by-step counting, being to count according to the level saltus step in train of pulse, encoder is defeated The pulse signal gone out is through analog digital conversion, and such as encoder rotates a circle and exports N number of sine wave, The most corresponding certain angular displacement of each sine wave, each sine wave is corresponding 2 pulses after analog digital conversion, Speed-measuring method the most of the prior art is not just ensuring that an impulse hits just correspondence 1/4th 1 this level is occurred in that between certain sampling instant K and a upper sampling instant K-1 in string ripple, such as figure Saltus step, in then judging this sampling time, electrical angle increment is as 90 °, correspond in sine wave it can be seen that This estimation has precision very poor, and big just because of this angle calculating error, and it is right further to limit Sample frequency and the requirement of electrode speed, this estimation requires that sample frequency can not too big or electrode speed Can not be the lowest, if such as sample frequency is quickly or electrode speed is the lowest, it is possible to a sampling time section The most do not sample level saltus step, then the speed calculated is exactly 0, therefore the testing the speed of prior art The measurement real-time of method also can reduce, and is appropriate only for high speed test.Therefore, the elevator of prior art is real-time Speed-measuring method is not suitable for low speed test, and rate accuracy has much room for improvement.

When elevator starts, in order to improve the whole apparatus for controlling elevator control performance in zero servo stage, need Direction and the load of load can be detected when load changing in time, and be given rapidly by feedback control With the moment of load balance, with ensure elevator device opening a sluice gate instantaneous proof load balance, cab will not rollback, Passenger has preferable comfort, thus improves the overall performance of apparatus for controlling elevator.Current elevator controlling system In system, the methods such as M method, T method and M/T method that tested the speed with low speed at a high speed are tested the speed, but these test the speed Method feeds back to speed ring after having to pass through low-pass filtering link, owing to filtering the existence of link, the speed of detection Degree is average speed, is not instantaneous velocity, the in the case of of changing for momentary load, the sound of whole control system Should be slower, it is impossible to meet the demand of on-the-spot actual application, and real time speed measuring method precision of the prior art is not High and test real-time is restricted, and is only applicable to high speed test, and when elevator starts, general speed ratio is relatively low, Therefore the real time speed measuring method of prior art is not suitable for.

Therefore, prior art existing defects, need to improve.

Summary of the invention

The technical problem to be solved in the present invention is, the above-mentioned real time speed measuring method for prior art is not suitable for Low speed test and rate accuracy speed-measuring method the highest, average are unfavorable for the defect of feedback control timely, it is provided that A kind of can realize real time speed measuring and the high elevator speed-measuring side of rate accuracy in the case of elevator low cruise Method, system and elevator low rate start control method.

The technical solution adopted for the present invention to solve the technical problems is: structure is a kind of based on sine and cosine encoder Elevator speed-measuring method, for the elevator of low cruise is carried out real time speed measuring, wherein, described method includes Following steps:

S1, the analogue signal of interval Preset Time Δ t sampling sine and cosine encoder output, during by present sample Engraving as t sampling instant, described analogue signal includes a-signal and the B signal of phase 90 °；

S2, read the code value y of described a-signal of t sampling instant_{<A, t>}Code value with described B signal y_{<B, t>}, and according to described code value y_{<A, t>}With code value y_{<B, t>}Calculate electrical angle θ of t sampling instant_t；

S3, electrical angle θ according to t sampling instant_t, electrical angle θ of previous t-1 sampling instant_t-1Calculate Go out electrical angle increment Delta θ in the Preset Time Δ t that t sampling instant is corresponding_t, and according to electrical angle increment Delta θ_t And Preset Time Δ t is calculated speed V of current sample time_t；

It is not over if S4 tests the speed, then goes to step S1, continue testing the speed of next sampling instant.

Elevator speed-measuring method of the present invention, wherein,

In described step S1, a-signal is sine wave signal, and B signal is cosine wave signal；

In described step S2, code value y_{<A, t>}With code value y_{<B, t>}Electrical angle θ with t sampling instant_tRelation For: y_{<A, t>}=sin θ_t/ code value precision, y_{<B, t>}=cos θ_t/ code value precision.

Elevator speed-measuring method of the present invention, wherein, described step S2 includes following sub-step:

S20, determine the code value accuracy class of a-signal and B signal；

S21, read the code value y of described a-signal in t sampling instant_{<A, t>}Code value with described B signal y_{<B, t>}, to described code value y_{<A, t>}With code value y_{<B, t>}It is filtered process and obtains code value Y_{(A, t)}And code value Y_{(B, t)}；

S22, by code value Y_{(A, t)}With code value Y_{(B, t)}Carry out zero point process and be converted to bipolarity code value；

S23, according in step S22 bipolarity code value calculate t sampling instant electrical angle θ_t, described electricity Angle, θ_tComputing formula be: θ_t=arctan (Y_{(A, t)}/Y_{(B, t)})。

Elevator speed-measuring method of the present invention, wherein, is filtered the formula processed in described step S21 As follows:

$Y_{<A,t>}=({\mathrm{\&Sigma;}}_{i=0}^{N-1}{y}_{<A,t-i>}-y_{<A,\max >}-y_{<A,\min >})/(N-2)$

$Y_{<B,t>}=({\mathrm{\&Sigma;}}_{i=0}^{N-1}{y}_{<B,t-i>}-y_{<B,\max >}-y_{<B,\min >})/(N-2)$

Wherein, N is integer and is more than or equal to 1, described y_{(A, t-i)}Represent that t sampling instant rises and elapse forward i The code value of the a-signal of individual sampling instant, y_{(A, max)}Represent that a-signal rises in t sampling instant and elapse forward N-1 Individual sampling instant is to the maximum in the N number of code value in current t sampling instant, y_{(A, max)}Represent A letter Number play N-1 sampling instant of passage forward to the N number of code value in current t sampling instant in t sampling instant In minima, y_{(B, t-i)}Represent that t sampling instant plays the code of the B signal of i sampling instant of passage forward Value, y_{(B, max)}Represent that B signal plays N-1 sampling instant of passage forward to current t in t sampling instant The maximum in N number of code value in sampling instant, y_{(B, min)}Represent that B signal rises forward in t sampling instant Elapse N-1 sampling instant to the minima in the N number of code value in current t sampling instant.

Elevator speed-measuring method of the present invention, wherein, if the whole sampling before t sampling instant time Number amounts to not enough n times, then the code value lacked all is defaulted as 0.

Elevator speed-measuring method of the present invention, wherein, described code value accuracy class and a-signal or B signal Theoretical maximum actual magnitude and theory minimum actual magnitude between relation be: 2^M=(MAX-MIN)/L, Wherein, MAX represents the theoretical maximum actual magnitude of a-signal or B signal, and MIN represents a-signal or B letter Number theoretical minimum actual magnitude, M represents code value accuracy class, and M is natural number and M >=6, and L represents code Value precision.

Elevator speed-measuring method of the present invention, wherein,

Described method also includes, before step S1, first rotary encoder one encloses, and record collects The code value Y that the theoretical minimum actual magnitude of a-signal or B signal is corresponding_off, going in described step S22 Zero point processes and includes: by code value Y_{(A, t)}With code value Y_{(B, t)}All deduct code value Y_off；

The bipolarity code value that is converted in described step S22 includes: will remove the code value Y after zero point_{(A, t)}And code Value Y_{(B, t)}Numerical value be individually subtracted 2^M-1。

Elevator speed-measuring method of the present invention, wherein,

Electrical angle increment Delta θ in described step S3_tFor: Δ θ_t=θ_t-θ_t-1；

Speed V_tComputing formula be: V_t=Δ θ_t/ Δ t,

If current sample time is the moment that sampling is corresponding for the first time, then θ_t-1Zero migration for encoder Angle.

The invention also discloses a kind of elevator speed-measuring system based on described elevator speed-measuring method, wherein, institute The system of stating includes:

Signal sampling module: for being spaced the analogue signal of Preset Time sampling sine and cosine encoder output, institute State analogue signal and include a-signal and the B signal of phase 90 °；

Code value accuracy class determines module: for determining the code value accuracy class of a-signal and B signal；

Code value read module: for reading under code value accuracy class determines the code value precision conditions that module limits The a-signal of signal sampling module acquisition and the code value of B signal；

Code value Filtering Processing module: process for the code value that code value read module reads is carried out zero point and turn It is changed to bipolarity code value；

Electrical angle computing module: calculate present sample according to the bipolarity code value that code value Filtering Processing module obtains The electrical angle in moment；

Speed calculation module: the electrical angle of the current sample time obtained according to electrical angle computing module and front The electrical angle of one sampling instant and Preset Time are calculated the speed of current sample time.

The invention also discloses a kind of elevator low rate start control method, wherein, described method includes:

Elevator speed-measuring method described in S10, utilization, obtains speed V of current sample time elevator_t, calculate The positional increment in Preset Time Δ t corresponding before current sample time is: θ_t-θ_t-1, and will currently adopt Positional increment summation corresponding to all sampling instants before the sample moment obtains the position of current time；

S20, the position of the current time fed back according to given position and step S10 determine the need for adjusting The given speed of output, if it is not required, then terminate, otherwise, adjusts the given speed of output；

S30, the given speed exported according to step S20 and speed V of step S10 feedback_tControl electric current defeated Go out and then adjust the speed of elevator, go to step S10.

Implement the elevator speed-measuring method of the present invention, system and elevator low rate start control method, have following Beneficial effect: the present invention is directly to calculate electrical angle according to analogue signal, owing to analogue signal is actual response Electrical angle change, therefore, compared with digital signal conversion, precision is greatly improved, on the other hand, Sample frequency is the highest more is conducive to the real-time of speed to measure, with digital signal, this requires that sample frequency can not be too high Comparing, more can embody the real-time of tachometric survey, time delay is little, and convergence is fast, and is not suitable for digital signal Low speed test is compared, and the method for the present invention is more suitable for low speed test.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described, in accompanying drawing:

Fig. 1 is prior art measuring principle figure；

Fig. 2 is the analogue signal schematic diagram in elevator speed-measuring method of the present invention；

Fig. 3 is the flow chart of the most preferred embodiment of elevator speed-measuring method of the present invention；

Fig. 4 is the structured flowchart of the most preferred embodiment of elevator speed-measuring system of the present invention；

Fig. 5 is the schematic diagram of elevator low rate start control method of the present invention.

Detailed description of the invention

In order to be more clearly understood from the technical characteristic of the present invention, purpose and effect, now comparison accompanying drawing is detailed Describe the detailed description of the invention of the bright present invention in detail.

The speed of motor can represent with the change of electrical angle in the unit interval, therefore, if electricity can be improved The precision of angular surveying, then can be effectively improved the precision that electrode speed is measured.The present invention is directly according to simulation Signal calculates electrical angle, and therefore, compared with digital signal conversion, precision is greatly improved, the opposing party Face, owing to analogue signal is the change of actual response electrical angle, therefore calculates electrical angle without limitation on to sampling The requirement of frequency.

The sine and cosine encoder that the present invention uses is Heidenhain 1387 encoder, the analogue signal bag of its output Include A, B, R, C, D signal.Wherein, a-signal and B signal phase 90 °, i.e. postpone 1/4 In the cycle, rotating can be distinguished according to delay relation；C signal is individual pen signal, i.e. encoder every revolution Send the C signal in a cycle.For Heidenhain 1387 encoder, encoder every revolution, a-signal Being respectively 2048 with the periodicity of B signal, a-signal is sinusoidal wave sin θ, and B signal is cosine wave cos θ, θ represent electrical angle.The speed of elevator motor is different, then the a-signal that encoder every revolution is corresponding is defeated Go out 2048 sinusoidal wave times also the most different.

For sinusoidal wave sin θ and cosine wave cos θ, although according to waveforms amplitude by arcsine or Person's anticosine computing can obtain the angle of correspondence, but owing to sin θ and cos θ are Non-monotonic functions, Therefore, the electrical angle that certain waveforms amplitude is corresponding can not be judged accurately, therefore by a-signal and B signal, The tan of dullness: tan θ=sin θ/cos θ, then carry out arctangent cp cp operation is obtained through Mathematical treatment I.e. can determine that electrical angle increment: θ=arctan (sin θ/cos θ).

Below in conjunction with Fig. 2 and Fig. 3, the concrete steps that the method for introduction relates to, it is right that the method for the present invention is applicable to The elevator of low cruise carries out real time speed measuring, is connected with sine and cosine encoder for example with DSP, compiles in DSP Cheng Shixian following steps, specifically include:

S1, the a-signal of interval Preset Time Δ t sampling sine and cosine encoder output and B signal, will be current Sampling instant is designated as t sampling instant.

In most preferred embodiment, Preset Time Δ t is 100 μ s, i.e. samples once every 100 μ s, above-mentioned carries Arriving, be finally intended to obtain calculating electrical angle through arctan function, therefore, Preset Time Δ t can not surpass Spend a sine wave or the cycle of cosine wave.The maximum speed that general synchrodrive runs is less than 300 turns / s, i.e. 0.0005 turn/100 μ s, then the a-signal sinusoidal wave number in a Preset Time Δ t is: 0.0005 turn/100 μ s × 2048/turn=1.024/100 μ s.Visible, even if taking maximum speed, A Signal the most corresponding 1.024 cycles in Preset Time Δ t, therefore for the motor of low cruise, Do not worry a Preset Time Δ t cycle more than an a-signal.

S2, referring to figs. 2 and 3, in most preferred embodiment, step S2 includes following sub-step S20-S23:

S20, determine the code value accuracy class of a-signal and B signal；

Code value accuracy class determines code value precision, described code value accuracy class and a-signal or the reason of B signal Relation between the maximum actual magnitude of opinion and theory minimum actual magnitude is: 2^M=(MAX-MIN)/L, its In, MAX represents the theoretical maximum actual magnitude of a-signal or B signal, and MIN represents a-signal or B signal Theoretical minimum actual magnitude, M represents code value accuracy class, M be natural number and, preferably M >=6, L It is code value precision for L.Will the theoretical maximum actual magnitude of sinusoidal wave (and cosine wave) and theory minimum real Distance between the amplitude of border is divided into 2^MPart.Due to theoretical maximum actual magnitude and theory minimum actual magnitude it Between distance be fixing, therefore, M is the biggest, and corresponding L is the least, and the precision calculating electrical angle is also got over High.

S21, read the code value y of described a-signal in t sampling instant_{<A, t>}Code value with described B signal y_{<B, t>}, to described code value y_{<A, t>}With code value y_{<B, t>}It is filtered process and obtains code value Y_{(A, t)}And code value Y_{(B, t)}；

Code value y_{<A, t>}With code value y_{<B, t>}Electrical angle θ with t sampling instant_tRelation be:

y_{<A, t>}=sin θ_t/ code value precision, y_{<B, t>}=cos θ_t/ code value precision；

Therefore,

y_{<A, t>}/y_{<B, t>}=sin θ_t/cosθ_t=tan θ_t,

Then, θ_t=arctan (y_{<A, t>}/y_{<B, t>}) (A)

S22, by code value Y_{(A, t)}With code value Y_{(B, t)}Carry out zero point process and be converted to bipolarity code value；

Although the formula (A) in step S21 just can calculate electrical angle, but in order to improve data Reliability, described step S2 is calculating electrical angle θ_tThe most also include described code value y_{<A, t>}And code value y_{<B, t>}It is filtered process and obtains code value Y_{(A, t)}With code value Y_{(B, t)},

The formula of described Filtering Processing is as follows:

$Y_{<A,t>}=({\mathrm{\&Sigma;}}_{i=0}^{N-1}{y}_{<A,t-i>}-y_{<A,\max >}-y_{<A,\min >})/(N-2)$

$Y_{<B,t>}=({\mathrm{\&Sigma;}}_{i=0}^{N-1}{y}_{<B,t-i>}-y_{<B,\max >}-y_{<B,\min >})/(N-2)$

Corresponding, electrical angle θ_tComputing formula be updated to the most accordingly:

θ_t=arctan (Y_{(A, t)}/Y_{(B, t)}) (B)

Wherein, N is integer and is more than or equal to 1, preferably 10, described y_{(A, t-i)}Represent that t sampling instant rises The code value of the a-signal of i sampling instant of passage forward, y_{(A, max)}Represent that a-signal rises in t sampling instant N-1 sampling instant of passage forward to the maximum in the N number of code value in current t sampling instant, y_{(A, min)}Represent that a-signal plays N-1 sampling instant of passage forward to current t sampling in t sampling instant The minima in N number of code value in moment, y_{(B, t-i)}Represent that t sampling instant plays i sampling of passage forward The code value of the B signal in moment, y_{(B, max)}Represent that B signal plays passage forward N-1 in t sampling instant and adopts The sample moment is to the maximum in the N number of code value in current t sampling instant, y_{(B, min)}Represent that B signal exists T sampling instant plays N-1 sampling instant of passage forward in the N number of code value in current t sampling instant Minima.

The code value y of the most current t sampling instant_{<A, t>}Put down with the code value in above N-1 moment of continuous print All Filtering Processing obtain the code value Y of t sampling instant_{(A, t)}, for the sampling several times started most, due to before it The number of times of surface sample not enough N-1, if the whole sampling number total therefore before current time is not Foot n times, then the code value lacked all is defaulted as 0, although so calculates the code value for initial time and reads by mistake Difference is very big, but Preset Time Δ t is 100 μ s, and sample frequency is the highest, and the speed calculation of start time is by mistake Difference is for the real time speed measuring process of whole subsequent process, and this error is negligible.

Further, the impact fluctuated due to other, the code value got not is theoretic code value.Cause This, the code value Y that Filtering Processing is obtained_{(A, t)}With code value Y_{(B, t)}It is necessary that carrying out zero point processes, reference Fig. 2, in most preferred embodiment, code value accuracy class is defined as 10, a most corresponding sine wave or The code value that the maximum of person's cosine wave is corresponding with minima is respectively as follows: 2048 and 0.But due to other disturbances Impact, the actual code value that maximum is corresponding with minima may be: 2148 and 100.Then survey therefore, Before speed, need first error identifying.

Method particularly includes: before step S1, first rotary encoder one encloses, the A letter that record collects Number or code value Y corresponding to the theoretical minimum actual magnitude of B signal_offGo zero point to process described in, to include: will Code value Y_{(A, t)}With code value Y_{(B, t)}All deduct code value Y_off。

Such as, the code value Y that Filtering Processing obtains sometime_{(A, t)}With code value Y_{(B, t)}It is respectively 2011 Hes 612, if then Y_offBe 100, then zero-suppress the code value Y after processing_{(A, t)}With code value Y_{(B, t)}It is respectively 1911 With 512.

But, above-mentioned go zero point process after code value Y_{(A, t)}With code value Y_{(B, t)}Be do not distinguish positive and negative, Can not directly carry out arctangent cp cp operation.It is thus desirable to by Y_{(A, t)}With code value Y_{(B, t)}It is reconverted into bipolar code Value.Be converted to bipolarity code value include: the code value Y after zero point will be removed_{(A, t)}With code value Y_{(B, t)}Numerical value divide Do not deduct 2^M-1。

Such as, the above-mentioned code value Y after going zero point to process_{(A, t)}With code value Y_{(B, t)}It is respectively 1911 With 612, then code value Y_{(A, t)}With code value Y_{(B, t)}Be converted to bipolarity code value: 1911-1024 and 612-1024, It is: 887 and-512.

It should be noted that code value accuracy class is the highest, the impact of interference is the biggest, so most preferred embodiment In be provided with special average filter step S22.If the code value accuracy class of step S20 is somewhat reduced, Then can save this filter step S22.Such as, in most preferred embodiment, code value accuracy class preferred 10, Interference is that the average filter by step S22 is disposed, it is also possible to code value accuracy class somewhat reduces changing into 8 or 9, and save average filter step S22.

S23, according in step S22 bipolarity code value calculate t sampling instant electrical angle θ_t。

Finally, the bipolarity code value obtained in above-mentioned steps S22 is substituted in formula (B), carries out anyway Cutting the electrical angle that computing obtains is arctan (-887/512)=60 °.

S3, electrical angle θ according to t sampling instant_t, electrical angle θ of previous t-1 sampling instant_t-1Calculate Go out electrical angle increment Delta θ in the Preset Time Δ t that t sampling instant is corresponding_t, and according to electrical angle increment Delta θ_t And Preset Time Δ t is calculated speed V of current sample time_t；

Electrical angle increment Delta θ_tFor: Δ θ_t=θ_t-θ_t-1；Speed V_tComputing formula be: V_t=Δ θ_t/Δt；

If current sample time is the moment that sampling is corresponding for the first time, then θ_t-1Zero migration for encoder Angle.

With reference to Fig. 4, the invention also discloses a kind of elevator based on elevator speed-measuring method of the present invention and survey Speed system, described system includes:

Signal sampling module: for being spaced the analogue signal of Preset Time sampling sine and cosine encoder output, institute State analogue signal and include a-signal and the B signal of phase 90 °.

Code value accuracy class determines module: for determining the code value accuracy class of a-signal and B signal；

Code value read module: for reading under code value accuracy class determines the code value precision conditions that module limits The a-signal of signal sampling module acquisition and the code value of B signal；

Code value Filtering Processing module: process for the code value that code value read module reads is carried out zero point and turn It is changed to bipolarity code value；

Electrical angle computing module: calculate present sample according to the bipolarity code value that code value Filtering Processing module obtains The electrical angle in moment；

Speed calculation module: the electrical angle of the current sample time obtained according to electrical angle computing module and front The electrical angle of one sampling instant and Preset Time are calculated the speed of current sample time.

The invention also discloses a kind of elevator low rate start control method, with reference to Fig. 5, the method is based on elevator System realize, elevator device includes: elevator speed-measuring system 200, control system 100, sine and cosine encoder, Motor；Wherein elevator speed-measuring system 200 is above-mentioned elevator speed-measuring system, except for the difference that, elevator speed-measuring system System 200 also includes position computation module；

The method of the present invention comprises the following steps:

S10, the speed calculation module of control system 100 calculate speed V of current sample time elevator_t, Positional increment in the Preset Time Δ t that position computation module is corresponding before calculating current sample time is: θ_t- θ_t-1, and when positional increment summation corresponding for all sampling instants before current sample time is obtained current The position carved, and respectively by speed V_tFeeding back to acceleration module, the position of current time feeds back to position mould Block；

S20, position module according in given position and step S10 position computation module feed back current time The position carved, it is determined whether need to adjust the given speed of output, if it is not required, then terminate, otherwise, Adjust the given speed of output；

Speed calculation mould in given speed that S30, acceleration module export according to step S20 and step S10 Speed V of block feedback_tControl the electric current output of current module, and then the speed of adjustment elevator, go to step S10.

In sum, the present invention is directly to calculate electrical angle according to analogue signal, owing to analogue signal is true Reaction electrical angle change, therefore, compared with digital signal conversion, precision is greatly improved, another Aspect, sample frequency is the highest more is conducive to the real-time of speed to measure, and this requires sample frequency not with digital signal Too high can compare, more can embody the real-time of tachometric survey, time delay is little, and convergence is fast, and with digital signal not Being applicable to low speed test compare, the method for the present invention is more suitable for low speed test.

Above in conjunction with accompanying drawing, embodiments of the invention are described, but the invention is not limited in above-mentioned Detailed description of the invention, above-mentioned detailed description of the invention is only schematic rather than restrictive, this The those of ordinary skill in field, under the enlightenment of the present invention, is being protected without departing from present inventive concept and claim Under the ambit protected, it may also be made that a lot of form, within these belong to the protection of the present invention.

Claims (8)

1. an elevator speed-measuring method based on sine and cosine encoder, for carrying out the elevator of low cruise Real time speed measuring, it is characterised in that said method comprising the steps of:

S1, the analogue signal of interval Preset Time Δ t sampling sine and cosine encoder output, during by present sample Engraving as t sampling instant, described analogue signal includes a-signal and the B signal of phase 90 °；

S2, read the code value y of described a-signal of t sampling instant_{(A, t)}Code value y with described B signal_{(B, t)}, And according to described code value y_{(A, t)}With code value y_{(B, t)}Calculate electrical angle θ of t sampling instant_t；

S3, electrical angle θ according to t sampling instant_t, electrical angle θ of previous sampling instant_t-1Calculate t Electrical angle increment Delta θ in the Preset Time Δ t that sampling instant is corresponding_t, and according to electrical angle increment Delta θ_tAnd Preset Time Δ t is calculated speed V of current sample time_t；

It is not over if S4 tests the speed, then goes to step S1, continue testing the speed of next sampling instant；

Wherein, in described step S1, a-signal is sine wave signal, and B signal is cosine wave signal；

In described step S2, code value y_{(A, t)}With code value y_{(B, t)}Electrical angle θ with t sampling instant_tRelation For: y_{(A, t)}=sin θ_t/ code value precision, y_{(B, t)}=cos θ_t/ code value precision；

Wherein, described step S2 includes following sub-step:

S20, determine the code value accuracy class of a-signal and B signal；

S21, read the code value y of described a-signal in t sampling instant_{(A, t)}Code value with described B signal y_{(B, t)}, to described code value y_{(A, t)}With code value y_{(B, t)}It is filtered process and obtains code value Y_{(A, t)}And code value Y_{(B, t)}；

S22, by code value Y_{(A, t)}With code value Y_{(B, t)}Carry out zero point process and be converted to bipolarity code value；

S23, according in step S22 bipolarity code value calculate t sampling instant electrical angle θ_t, described electricity Angle, θ_tComputing formula be: θ_t=arctan (Y_{(A, t)}/Y_{(B, t)})。

Elevator speed-measuring method the most according to claim 1, it is characterised in that in described step S21 The formula being filtered processing is as follows:

$Y_{(A,t)}=({\mathrm{\&Sigma;}}_{i=0}^{N-1}{y}_{(A,t-i)}-y_{(A,max)}-y_{(A,min)})/(N-2)$

$Y_{(B,t)}=({\mathrm{\&Sigma;}}_{i=0}^{N-1}{y}_{(B,t-i)}-y_{(B,max)}-y_{(B,min)})/(N-2)$

Wherein, N is integer and is more than or equal to 1, described y_{(A, t-i)}Represent that t sampling instant rises and elapse forward i The code value of the a-signal of individual sampling instant, y_{(A, max)}Represent that a-signal rises in t sampling instant and elapse forward N-1 Individual sampling instant is to the maximum in the N number of code value in current t sampling instant, y_{(A, min)}Represent A letter Number play N-1 sampling instant of passage forward to the N number of code value in current t sampling instant in t sampling instant In minima, y_{(B, t-i)}Represent that t sampling instant plays the code of the B signal of i sampling instant of passage forward Value, y_{(B, max)}Represent that B signal plays N-1 sampling instant of passage forward to current t in t sampling instant The maximum in N number of code value in sampling instant, y_{(B, min)}Represent that B signal rises forward in t sampling instant Elapse N-1 sampling instant to the minima in the N number of code value in current t sampling instant.

Elevator speed-measuring method the most according to claim 2, it is characterised in that if t sampling instant Whole sampling number before amounts to not enough n times, then the code value lacked all is defaulted as 0.

Elevator speed-measuring method the most according to claim 1, it is characterised in that described code value precision etc. Relation between level and the theoretical maximum actual magnitude of a-signal or B signal and theory minimum actual magnitude is: 2^M=(MAX-MIN)/L, wherein, MAX represents the theoretical maximum actual magnitude of a-signal or B signal, MIN represents the theoretical minimum actual magnitude of a-signal or B signal, and M represents code value accuracy class, and M is certainly So number and M >=6, L represents code value precision.

Elevator speed-measuring method the most according to claim 1, it is characterised in that

Described method also includes, before step S1, first rotary encoder one encloses, and record collects The code value Y that the theoretical minimum actual magnitude of a-signal or B signal is corresponding_off, going in described step S22 Zero point processes and includes: by code value Y_{(A, t)}With code value Y_{(B, t)}All deduct code value Y_off；

The bipolarity code value that is converted in described step S22 includes: will remove the code value Y after zero point_{(A, t)}And code Value Y_{(B, t)}Numerical value be individually subtracted 2^M-1。

Elevator speed-measuring method the most according to claim 1, it is characterised in that

Electrical angle increment Delta θ in described step S3_tFor: Δ θ_t=θ_t-θ_t-1；

Speed V_tComputing formula be: V_t=Δ θ_t/ Δ t,

If current sample time is the moment that sampling is corresponding for the first time, then θ_t-1Zero migration for encoder Angle.

7. an elevator speed-measuring system based on the elevator speed-measuring method described in any one of claim 1-6, It is characterized in that, described system includes:

Signal sampling module: for being spaced the analogue signal of Preset Time sampling sine and cosine encoder output, institute State analogue signal and include a-signal and the B signal of phase 90 °；

Code value accuracy class determines module: for determining the code value accuracy class of a-signal and B signal；

Code value read module: for reading under code value accuracy class determines the code value precision conditions that module limits The a-signal of signal sampling module acquisition and the code value of B signal；

Code value Filtering Processing module: process for the code value that code value read module reads is carried out zero point and turn It is changed to bipolarity code value；

Electrical angle computing module: calculate present sample according to the bipolarity code value that code value Filtering Processing module obtains The electrical angle in moment；

Speed calculation module: the electrical angle of the current sample time obtained according to electrical angle computing module and front The electrical angle of one sampling instant and Preset Time are calculated the speed of current sample time.

8. an elevator low rate start control method, it is characterised in that described method includes:

S10, utilize the elevator speed-measuring method described in any one of claim 1-6, obtain current sample time Speed V of elevator_t, the positional increment in Preset Time Δ t corresponding before calculating current sample time is: θ_t-θ_t-1, and positional increment summation corresponding for all sampling instants before current sample time is obtained current The position in moment；

S20, the position of the current time fed back according to given position and step S10 determine the need for adjusting The given speed of output, if it is not required, then terminate, otherwise, adjusts the given speed of output；

S30, the given speed exported according to step S20 and speed V of step S10 feedback_tControl electric current defeated Go out and then adjust the speed of elevator, go to step S10.