CN103048071B - Device and method for monitoring dynamic torque of frameless torque motor in suspension state - Google Patents

Abstract

The invention relates to a device for monitoring dynamic torque of a frameless torque motor in a suspension state, which comprises a non-contact photoelectric encoder arranged on the frameless torque motor, a signal conversion and preprocessing circuit, a high-speed data acquisition card and a calculation and analysis data unit, wherein the signal conversion and preprocessing circuit, the high-speed data acquisition card and the calculation and analysis data unit are arranged in an upper computer; the non-contact photoelectric encoder comprises a circular grating disc and a reading head; the circular grating disc is fixedly connected with a rotating part of the frameless torque motor in a coaxial line manner, and the reading head is fixedly connected to the fixed seat; the reading head can acquire dynamic angular displacement data of a rotating part of the frameless torque motor in real time, and the dynamic torque output value and the rotating speed of the frameless torque motor are displayed in real time through signal processing and data analysis.

Description

Device and method for monitoring dynamic torque of frameless torque motor in suspension state

technical field

The invention relates to a measuring device for real-time monitoring of the dynamic torque of a frameless torque motor in a suspended state.

Background technique

The torque motor has the characteristics of low speed, high torque, strong overload capacity, fast response, good characteristic linearity, and small torque fluctuation. It can directly drive the load without the intermediate transmission mechanism, thereby improving the operating accuracy of the system. Therefore, it is widely used in industrial fields such as textile, wire and cable, metal processing, paper making, rubber, plastic and printing machinery.

The torque output value is a typical parameter that characterizes the performance and working state of the torque motor drive, and its measurement has important significance. However, the existing method for measuring the output torque of the torque motor is only suitable for measuring the static torque, even if the dynamic torque can be measured, there is a defect of inaccurate measurement due to the inability to accurately measure the angular acceleration and friction torque. According to the measurement method of the sensor, it is generally divided into two types: contact type and non-contact type. Contact sensors are mainly strain gauge torque sensors, and non-contact sensors are mainly divided into two categories: magnetoelectric and photoelectric. The strain gauge torque sensor measures the torque by measuring the deformation of the elastic element through the strain gauge. This measurement method is greatly affected by the material and shape of the elastic shaft. In principle, it is difficult to continue to improve the resolution, and this test method And the device is only suitable for analyzing and measuring the static torque on the material under the condition of static force. For the non-contact sensor to measure the torque, the magnetoelectric sensor is affected by the ambient temperature and the external magnetic field, the sensitivity will change and the measurement error will occur. For the micro torque, the error is usually large or even impossible to measure. The above two methods, due to the inability Accurately measure angular acceleration and frictional torque, so there is a defect of inaccurate dynamic torque measurement, and the existing technology cannot accurately measure the real-time dynamic torque output by the torque motor. At present, there is no device and method suitable for monitoring the dynamic torque of the frameless torque motor in the suspension state, and the data of dynamic torque is of great significance for calibrating the performance of the frameless torque motor in the suspension state, so it is required to adopt a new The principle realizes the real-time measurement of dynamic torque.

Contents of the invention

The technical problem to be solved by the present invention is to avoid the deficiencies of the prior art, and to provide a high-precision, non-contact device that uses a photoelectric encoder to monitor the dynamic torque of a frameless torque motor in a suspended state. As far as the frameless torque motor is concerned, since its rotating parts are in a suspended state, the friction force is very small and can be ignored. This device can monitor and display the real-time output state of the dynamic torque of the frameless torque motor in the suspended state.

The principle on which the present invention is based is shown in formula (1):

T _k ＝ J _total ε _k + T _f (1)

In the formula, J is _always the total moment of inertia of the rotating object on the air-bearing main shaft, ε _k is the angular acceleration value at the kth sampling time, and T _f is the friction torque caused by the friction force.

The calculation formula of ε _k is as follows:

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In the formula, ω _k is the angular velocity at the kth sampling, ωk _-1 is the angular velocity at the k-1th sampling, and T is the sampling period

The calculation formula of ω _k is as follows:

${\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In the formula, θ _k is the angle change value at the k-th sampling period, and θ _k-1 is the angle change value at the k-1 sampling period of the high-precision optical angular displacement measurement sensor.

From the formulas (2) and (3), it can be deduced that:

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

T _f is the torque caused by friction. Since this device uses a non-contact photoelectric encoder to measure the dynamic torque of the frameless torque motor in the suspension state, the value of T _f is very small and can be ignored. Therefore, the calculation of the motor output torque The formula translates to

Through data analysis and calculation software, the angular displacement signal read by the encoder is converted into a torque value and output on the interface in real time, with extremely high precision.

In order to solve the above-mentioned technical problems, the present invention is realized in the following manner: a device for monitoring the dynamic torque of a frameless torque motor in a suspension state according to the present invention includes a non-contact photoelectric encoder installed on the frameless torque motor device and signal conversion and preprocessing circuit, high-speed data acquisition card, and calculation and analysis data unit installed inside the host computer; the frameless torque motor is fixed on the motor base; the non-contact photoelectric encoder includes a circular grating disk and the reading head; the circular grating disk is fixedly connected to the rotating part of the frameless torque motor on the coaxial line, and rotates synchronously with the rotating part of the frameless torque motor; the reading head is fixedly connected to the fixed seat; the reading head It is aligned with the grating ruler on the circular grating disk to ensure that the dynamic angular displacement data of the rotating parts of the frameless torque motor can be collected correctly in real time; the reading head is electrically connected with the signal conversion and preprocessing circuit through the data line; the reading head The dynamic angular displacement data of the rotating parts of the frameless torque motor collected by the head in real time is transmitted to the high-speed data acquisition card after signal conversion and preprocessing circuit processing, and the data in the high-speed data acquisition card is analyzed by the calculation and analysis data unit After calculation and control, the dynamic torque output value and speed of the frameless torque motor are displayed in real time.

The distance between the reading head and the circular grating disc is 0.8 mm.

The dynamic angular displacement data of the rotating parts of the frameless torque motor collected by the reading head in real time is a pulse signal, which is converted into an analog signal by a signal conversion and preprocessing circuit.

A method for performing a dynamic torque test using a device for monitoring the dynamic torque of a frameless torque motor in a suspended state: it is characterized in that it includes the following steps:

1) Set the real-time data acquisition cycle T through the host computer;

2) Collect the dynamic angular displacement change data θ _k-2 , θ _k-1 , θ _k of the rotating parts of the frameless torque motor in three consecutive periods through a non-contact photoelectric encoder;

3) Analyze the data unit by calculation and use the formula and Analyzing and processing the data collected in the above step 2) to obtain the angular acceleration value ${\mathrm{\&epsiv;}}_k=\frac{{\mathrm{\&theta;}}_k-{\mathrm{\&theta;}}_{k-1}-({\mathrm{\&theta;}}_{k-1}-{\mathrm{\&theta;}}_{k-2})}{T\&CenterDot;T}=\frac{{\mathrm{\&theta;}}_k-2{\mathrm{\&theta;}}_{k-1}+{\mathrm{\&theta;}}_{k-2}}{T^2},$ According to the formula T _k = J _total ε _k + T _f , where T _f is very small for the frameless torque motor working in this suspension state and can be ignored, the torque output in the kth cycle can be calculated value T _k , so that the real-time dynamic torque of the frameless torque motor can be measured;

4) Display the dynamic torque output value and speed of the frameless torque motor through the host computer.

The positive effect of the present invention: the device for monitoring the dynamic torque of the frameless torque motor under the suspension state according to the present invention adopts a high-precision, non-contact photoelectric encoder, and through signal processing and data analysis, the Real-time monitoring of the dynamic torque of the frameless torque motor. The monitoring data is of great significance for calibrating the performance of the frameless torque motor in the suspension state. With the further development of science and technology and the further improvement of computing power, the device can The scale of the disk is further refined, and the sampling period value T is greatly shortened, so that the monitoring accuracy of the device can be greatly improved, and different motor bases can be used according to different types of frameless torque motors, which has better performance. adaptability.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic structural diagram of the present invention for monitoring the dynamic torque of a frameless torque motor in an air-floating state

In the figure, 1 reading head 2 circular grating disc 3 air bearing

4 Air bearing spindle 5 Frameless torque motor 6 Motor base

Detailed ways

As shown in Figure 1, it is a schematic diagram of the installation structure when the present invention is used to monitor the dynamic torque of the frameless torque motor under the air-floating state, the measured frameless torque motor (5) directly drives the air-floating main shaft (4), and the air-floating main shaft ( 4) A nearly frictionless suspension state is realized through the support of the air bearing (3), the circular grating disc (2) is fixedly connected with the coaxial line of the air bearing (4), and rotates synchronously with the air bearing (4); the reading The head (1) is aligned with the grating scale on the circular grating disk (2), ensuring that the dynamic angular displacement data of the air bearing spindle (4) driven by the frameless torque motor (5) can be correctly collected in real time; the reading head ( 1) The electrical connection is formed through the data line and the signal conversion and preprocessing circuit; the dynamic angular displacement data of the air bearing spindle (4) collected by the reading head (1) in real time is transmitted to the high-speed data after being processed by the signal conversion and preprocessing circuit Acquisition card, and after the data in the high-speed data acquisition card is analyzed and controlled by the calculation and analysis data unit, the dynamic torque output value and rotational speed of the frameless torque motor in the air-floating state are displayed in real time; the reading head (1) The dynamic angular displacement data of the air bearing spindle (4) collected in real time is a pulse signal, which is converted into an analog signal by a signal conversion and preprocessing circuit, and transmitted to a high-speed data acquisition card.

The method of using the present invention to monitor the dynamic torque of the frameless torque motor in the air-floating state: it is characterized in that it includes the following steps:

1) Set the real-time data acquisition cycle T through the host computer;

2) Collect the dynamic angular position change data θ _k-2 , θ _k-1 , θ _k of the air bearing spindle (4) in three consecutive cycles through the circular grating disc (5) and the reading head (6);

3) By calculating and analyzing the data unit, use the following formula

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

The data collected in the above step 2) is analyzed and processed to obtain the angular acceleration ε _k value of the kth cycle, and then through the calculation formula

T _k ＝ J _total ε _k + T _f

Calculate the torque output value T _k in the kth cycle, where T _f is very small for the rotating parts of the frameless torque motor in this air-floating state and can be ignored, so that the real-time frameless torque can be measured The dynamic torque of the motor.

4) Display the dynamic torque output value and speed of the frameless torque motor through the host computer.

When the frameless torque motor dynamic torque monitoring device in the air-floating state in this embodiment is in use, different motor bases (6) can be selected according to different types of frameless torque motors, so it has good applicability. Non-contact grating encoders with different precision can also be selected to meet different precision requirements.

The above is only a specific application example of the device and method for monitoring the dynamic torque of the frameless torque motor under the suspension state related to the present invention with illustrations, because it is easy for those skilled in the same technical field to Therefore, this specification does not intend to limit the device and method for monitoring the dynamic torque of the frameless torque motor in the suspension state in the present invention to the specific mechanism and scope of application shown or described, so any Corresponding modifications and equivalents that may be utilized all belong to the protection scope of the patent of the present invention.

Claims (3)

1. A method for monitoring the dynamic torque of the frameless torque motor under the suspended state, characterized in that: the method is realized by a device for monitoring the dynamic torque of the frameless torque motor under the suspended state, the device comprising The non-contact photoelectric encoder installed on the frameless torque motor and the signal conversion and preprocessing circuit installed inside the host computer, high-speed data acquisition card, calculation and analysis data unit; the frameless torque motor is fixed on the motor base The non-contact photoelectric encoder includes a circular grating disc and a reading head; the circular grating disc is fixedly connected with the rotating part of the frameless torque motor on the coaxial line, and rotates synchronously with the rotating part of the frameless torque motor; The reading head is fixedly connected to the fixed seat; the reading head is aligned with the grating scale on the circular grating disc to ensure that the dynamic angular displacement data of the rotating parts of the frameless torque motor can be collected correctly in real time; the reading head passes through the data line It is electrically connected with the signal conversion and pre-processing circuit; the dynamic angular displacement data of the rotating parts of the frameless torque motor collected by the reading head in real time is transmitted to the high-speed data acquisition card after being processed by the signal conversion and pre-processing circuit, and passed through After the calculation and analysis data unit analyzes and controls the data in the high-speed data acquisition card, it displays the dynamic torque output value and speed of the frameless torque motor in real time; Described method comprises the steps: 1) Set the real-time data acquisition cycle T through the host computer; 2) Collect the dynamic angular displacement change data θ _k-2 , θ _k-1 , θ _k of the rotating parts of the frameless torque motor in three consecutive periods through a non-contact photoelectric encoder; 3) Analyze the data unit by calculation and use the formula and Analyzing and processing the data collected in the above step 2) to obtain the angular acceleration value ${\mathrm{\&epsiv;}}_k=\frac{{\mathrm{\&theta;}}_k-{\mathrm{\&theta;}}_{k-1}-({\mathrm{\&theta;}}_{k-1}-{\mathrm{\&theta;}}_{k-2})}{T\&CenterDot;T}=\frac{{\mathrm{\&theta;}}_k-2{\mathrm{\&theta;}}_{k-1}+{\mathrm{\&theta;}}_{k-2}}{T^2},$ Through the formula T _k = J _total ε _k + T _f , where J _total is the total moment of inertia of the rotating object on the main axis of the air bearing, ω _k is the angular velocity at the kth sampling, and ε _k is the angle at the kth sampling Acceleration value, T _f is the friction torque caused by the friction force, T _f is very small for the frameless torque motor working in this suspension state, that is, calculate the torque output value T _k in the kth cycle, and then measure Get real-time dynamic torque of frameless torque motor; 4) Display the dynamic torque output value and speed of the frameless torque motor through the host computer. 2. The method for monitoring the dynamic torque of a frameless torque motor in a suspended state according to claim 1, wherein the distance between the reading head and the circular grating disk is 0.8mm. 3. The method for monitoring the dynamic torque of the frameless torque motor under the suspended state according to claim 1, characterized in that: the dynamic angular displacement data of the rotating parts of the frameless torque motor collected by the reading head in real time is pulse Signal, which is converted into an analog signal through a signal conversion and preprocessing circuit.