CN108151637B

CN108151637B - Displacement detection device, magnetic suspension bearing and displacement detection method thereof

Info

Publication number: CN108151637B
Application number: CN201711001946.XA
Authority: CN
Inventors: 汪波; 贺永玲; 赵聪
Original assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Current assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Priority date: 2017-10-24
Filing date: 2017-10-24
Publication date: 2020-04-14
Anticipated expiration: 2037-10-24
Also published as: CN108151637A

Abstract

The invention discloses a displacement detection device, a magnetic suspension bearing and a displacement detection method thereof, wherein the device comprises: redundant sensors and control mechanisms; the redundant sensor is arranged on each degree of freedom of the bearing (1) to be detected and used for redundantly acquiring displacement signals of the bearing (1) on the degree of freedom; and the control mechanism is used for controlling the operation condition of the degree of freedom to which the displacement signal belongs based on the displacement signal obtained in a redundant manner. The scheme of the invention can overcome the defects of large resource occupation, complex structure, low reliability and the like in the prior art, and realize the beneficial effects of small resource occupation, simple structure and high reliability.

Description

Displacement detection device, magnetic suspension bearing and displacement detection method thereof

Technical Field

The invention belongs to the technical field of magnetic suspension, and particularly relates to a displacement detection device, a magnetic suspension bearing and a displacement detection method thereof, a redundant design device for displacement detection, a magnetic suspension bearing with the device and a redundant design method for displacement detection of the magnetic suspension bearing.

Background

With the gradual application of the magnetic suspension bearing, the reliability of the magnetic suspension bearing becomes more and more important, and the redundancy design is an effective way for improving the reliability of a magnetic suspension bearing system. The magnetic suspension bearing system is controlled by double rings, an inner ring current ring and an outer ring displacement ring. And displacement detection is a very important component in the displacement ring. For a conventional magnetic suspension bearing system, once the displacement detection fails, the whole magnetic suspension bearing system cannot normally operate.

At present, although a redundancy design method of a sensor is available, the existing redundancy design method has certain limitations. For example: the magnetic bearing sensor control system with fault-tolerant function, however, the magnetic bearing sensor control system is a magnetic bearing sensor control system which performs differential operation by software, thus occupying CPU kernel resources, and requiring 2 AD channels in one degree of freedom, while the magnetic suspension bearing has 5 degrees of freedom, requiring 10 AD channels; in addition to some temperature and bus voltage monitoring, the whole system needs dozens of AD channels. However, the MCU in the market does not have so many AD channels, so the system has great limitation. The main limitation is that the AD channel occupies too much, and the mainstream MCU chip cannot be realized; secondly, software resources are occupied.

In the prior art, the defects of large resource occupation, complex structure, low reliability and the like exist.

Disclosure of Invention

The invention aims to provide a displacement detection device, a magnetic suspension bearing and a displacement detection method thereof aiming at the defects, so as to solve the problem of large resource occupation caused by excessive AD channels in the prior art and achieve the effect of reducing the resource occupation.

The present invention provides a displacement detection device, including: redundant sensors and control mechanisms; the redundant sensor is arranged on each degree of freedom of the bearing to be detected and used for redundantly acquiring displacement signals of the bearing on the degree of freedom; and the control mechanism is used for controlling the operation condition of the degree of freedom to which the displacement signal belongs based on the displacement signal obtained in a redundant manner.

Optionally, wherein the redundant sensor comprises: two sensors; the two sensors are symmetrically arranged at two ends of each degree of freedom of the bearing; and/or each sensor is arranged at a distance from the shaft of the bearing.

Optionally, wherein each of the sensors comprises: an eddy current sensor; and/or, the bearing, comprising: a magnetic suspension bearing; and/or an air gap is arranged between the bearing and the shaft of the bearing.

Optionally, the degrees of freedom in which the redundant sensor is provided comprise: a radial degree of freedom and/or an axial degree of freedom; wherein the radial degree of freedom comprises: a front radial degree of freedom and a rear radial degree of freedom respectively distributed forward and backward with respect to the axial degree of freedom; the anterior radial degree of freedom and the posterior radial degree of freedom each include: an X-direction degree of freedom and a Y-direction degree of freedom; the axial degree of freedom includes: z-direction freedom.

Optionally, the control mechanism comprises: a differential circuit, a selection circuit and a controller; wherein, the control mechanism controls the running condition of the unit to which the bearing belongs, and comprises: the differential circuit is used for carrying out differential processing on the displacement signals obtained in a redundant mode to obtain differential signals; the selection circuit is used for switching on the switch channels corresponding to the differential signals in an initial state under the control of the controller so as to input the differential signals to the controller as initial input signals; the controller is used for determining whether the initial input signal meets a first normal value set by a corresponding switch channel; and if the initial input signal meets the first normal value, controlling the unit to operate by using an initial setting program.

Optionally, the control mechanism controls an operation condition of the unit to which the bearing belongs, and further includes: the selection circuit is further configured to switch on any one of switch channels corresponding to the displacement signals obtained redundantly when the initial input signal does not meet the first normal value, so that any one of the displacement signals obtained redundantly is input to the controller as a second input signal; the controller is further configured to determine whether the second input signal satisfies a second normal value set by a corresponding switch channel if the initial input signal does not satisfy the first normal value; and if the second input signal meets the second normal value, the initial setting program is switched to a second setting program corresponding to the corresponding switch channel to control the unit to operate.

Optionally, the control mechanism controls an operation condition of the unit to which the bearing belongs, and further includes: the selection circuit is further configured to switch on another switch channel in the switch channels corresponding to the displacement signals obtained redundantly when the second input signal does not meet the second normal value, so as to use another path of signals in the displacement signals obtained redundantly as a third input signal to the controller; repeating the operation until all paths of signals corresponding to the displacement signals redundantly acquired in the degree of freedom of the controller are input into the controller as corresponding input signals; the controller is further configured to determine whether the third input signal satisfies a third normal value set by a corresponding switch channel if the second input signal does not satisfy the second normal value; if the third input signal meets the third normal value, the second setting program is switched to a third setting program corresponding to the corresponding switch channel to control the unit to operate; and the rest is repeated until all the input signals on the degree of freedom of the input signals meet the corresponding normal values of the corresponding switch channels.

Optionally, the control mechanism controls an operation condition of the unit to which the bearing belongs, and further includes: the controller on any one degree of freedom is further used for controlling the unit to stop and starting a first warning signal of the unit fault if the initial input signal on any one degree of freedom does not meet the first normal value and each path of signal in the displacement signal redundantly acquired on the degree of freedom does not meet the corresponding normal value set by the corresponding switch channel; or if the initial input signal on any degree of freedom does not meet the first normal value, but at least one path of signals in the displacement signals obtained redundantly on all degrees of freedom meets the corresponding normal value set by the corresponding switch channel, controlling the unit to continue to operate, and initiating a second warning signal that the initial input signal on the corresponding degree of freedom does not meet the first normal value.

Optionally, the control mechanism further includes: a signal conditioning circuit; the number of the signal conditioning circuits is the same as that of the redundant sensors; each signal conditioning circuit is configured to perform at least one of filtering and amplifying on a corresponding path of signal in the redundantly obtained displacement signals, and then transmit the processed signal to at least one of the differential circuit and the selection circuit; and/or the differential circuit is also used for amplifying the differential signal; and/or, the selection circuit comprises: a selection switch and an AD sampling channel; the selection switch is used for switching on a path of signal in the corresponding switch channels of the displacement signal and the differential signal obtained by self redundancy; and the AD sampling channel is used for enabling the controller to sample the signal from one switch channel switched on by the selection switch.

Optionally, when the sensor comprises an eddy current sensor, each of the signal conditioning circuits comprises: a filter circuit, and/or a pre-set circuit of the eddy current sensor.

In accordance with the above device, another aspect of the present invention provides a magnetic suspension bearing, including: the displacement detecting device described above.

In another aspect, the present invention provides a method for detecting displacement of a magnetic suspension bearing, including: the collection step comprises: redundantly acquiring displacement signals of the bearings on the degrees of freedom to which the bearings belong; the control steps are as follows: and controlling the operation condition of the degree of freedom to which the displacement signal belongs based on the redundantly obtained displacement signal.

Optionally, the controlling step includes: a difference processing step: carrying out differential processing on the displacement signals obtained in a redundant mode to obtain differential signals; signal gating step: switching on a switch channel corresponding to the differential signal in an initial state to take the differential signal as an initial input signal; or when the initial input signal does not meet the first normal value, switching on any one of switch channels corresponding to the displacement signals obtained redundantly so as to take any one of the displacement signals obtained redundantly as a second input signal; or when the second input signal does not meet the second normal value, switching on another switch channel in the switch channels corresponding to the displacement signals obtained in a redundant mode, so that another path of signals in the displacement signals obtained in a redundant mode is used as a third input signal; repeating the operation until all paths of signals corresponding to the displacement signals which are redundantly obtained on the degrees of freedom of the operation are input as corresponding input signals; a signal processing step: determining whether the initial input signal meets a first normal value set by a corresponding switch channel; if the initial input signal meets the first normal value, controlling the unit to operate by an initial setting program; if the initial input signal does not meet the first normal value, determining whether the second input signal meets a second normal value set by a corresponding switch channel; if the second input signal meets the second normal value, the initial setting program is switched to a second setting program corresponding to the corresponding switch channel to control the unit to operate; if the second input signal does not meet the second normal value, determining whether the third input signal meets a third normal value set by a corresponding switch channel; if the third input signal meets the third normal value, the second setting program is switched to a third setting program corresponding to the corresponding switch channel to control the unit to operate; and the rest is repeated until all the input signals on the degree of freedom of the input signals meet the corresponding normal values of the corresponding switch channels.

Optionally, the controlling step further includes: initiating a warning step: if the initial input signal on any one degree of freedom does not meet the first normal value and each path of signal in the displacement signal redundantly acquired on the degree of freedom does not meet the corresponding normal value set by the corresponding switch channel, controlling the unit to stop and starting a first warning signal of the unit fault; or if the initial input signal on any degree of freedom does not meet the first normal value, but at least one path of signals in the displacement signals obtained redundantly on all degrees of freedom meets the corresponding normal value set by the corresponding switch channel, controlling the unit to continue to operate, and initiating a second warning signal that the initial input signal on the corresponding degree of freedom does not meet the first normal value; and/or, a signal conditioning step: and carrying out at least one of filtering and amplifying on corresponding path signals in the displacement signals obtained redundantly, and then carrying out at least one of differential processing and signal gating processing.

Optionally, the differential processing step further includes: amplifying the differential signal; and/or, the signal gating step further comprises: switching on a signal in the corresponding switch channel of the displacement signal and the differential signal obtained by self redundancy; and sampling the signal from the switched-on switch channel.

The scheme of the invention improves the reliability of the magnetic suspension system, reduces the resources occupied by the CPU kernel and reduces the number of the required AD channels through the redundancy design.

Further, the scheme of the invention only needs 5 AD channels in total by arranging two sensors in each degree of freedom, thereby reducing the number of AD channels.

Furthermore, the scheme of the invention carries out differential processing through the hardware circuit without occupying CPU kernel resources, thereby reducing the CPU kernel resource occupation.

Therefore, according to the scheme provided by the invention, the number of the AD sampling channels is reduced by arranging the redundant sensors at each degree of freedom, and the problem of large resource occupation caused by excessive AD channels in the prior art is solved, so that the defects of large resource occupation, complex structure and low reliability in the prior art are overcome, and the beneficial effects of small resource occupation, simple structure and high reliability are realized.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a schematic view of an embodiment of a radial sensor arrangement of the displacement detecting device of the present invention;

FIG. 2 is a schematic diagram of an arrangement of an axial sensor in the displacement detecting device according to an embodiment of the present invention;

FIG. 3 is a schematic circuit diagram of a displacement detecting device according to an embodiment of the present invention; the first channel is an output channel of the first signal conditioning circuit, the second channel is an output channel of the second signal conditioning circuit, and the third channel is an output channel of the differential circuit.

The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:

1-a bearing; 2-an air gap; 3-axis; a 41-X + direction sensor; a 42-X-direction sensor; a 43-Y + direction sensor; a 44-Y-direction sensor; a 45-Z + direction sensor; a 46-Z-direction sensor; 51-a first signal conditioning circuit; 52-second signal conditioning circuitry; 6-a differential circuit; 7-a selection switch; 8-AD sampling channel; 9-a controller.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, there is provided a displacement detecting device. The displacement detecting device may include: redundant sensors and control mechanisms.

In an alternative example, the redundant sensor, which is provided at each degree of freedom of the bearing 1 to be detected, may be used to redundantly obtain the displacement signal of the bearing 1 at the degree of freedom.

Optionally, the redundant sensor may include: two sensors. And the two sensors are symmetrically arranged at two ends of each degree of freedom of the bearing 1.

The number of sensors in each degree of freedom may be two or more. More than two sensors need to be provided with corresponding programs for control.

Therefore, the two sensors are arranged on each degree of freedom, so that the accuracy of displacement signal acquisition of each degree of freedom and the reliability of running of the unit to which the bearing belongs can be improved.

Optionally, each of the sensors is spaced from the shaft 3 of the bearing 1.

For example: the sensor is spaced apart from (i.e., not in contact with) the shaft.

Therefore, the sensor and the bearing are arranged at intervals, so that the displacement signal can be acquired under the condition that the operation of the bearing is not influenced, the acquisition mode is simple and convenient, and the accuracy of the acquisition result is good.

Optionally, each of the sensors may include: an eddy current sensor.

Therefore, the electric eddy current sensor is used, and the reliability and the safety of acquiring the displacement signal are high.

For example: the distance between the sensor and the shaft is correspondingly limited and can be set according to actual requirements. For example: typically, eddy current sensors are relatively short in distance. For example, the distance between the eddy current sensor and the shaft can be set to be between 15um and 50um, and of course, the distance can also be set according to actual needs.

Therefore, the distance between the eddy current sensor and the shaft of the bearing is set to be 15-50um, so that the mounting structure of the eddy current sensor is reasonable, and the working reliability is guaranteed.

Alternatively, the bearing 1 may include: provided is a magnetic suspension bearing.

Therefore, the magnetic suspension bearing and the unit to which the magnetic suspension bearing belongs can be controlled conveniently and reliably by carrying out redundancy design on displacement detection of the magnetic suspension bearing.

Optionally, an air gap 2 is provided between the bearing 1 and its shaft.

Therefore, the air gap is arranged between the bearing and the shaft of the bearing, so that the action performance between the bearing and the shaft of the bearing can be improved, and the bearing has high reliability and good safety.

Optionally, the degree of freedom in which the redundant sensor is provided may include: a radial degree of freedom and/or an axial degree of freedom.

In an alternative specific example, the radial degree of freedom may include: a front radial degree of freedom and a rear radial degree of freedom respectively distributed front and rear with respect to the axial degree of freedom. The anterior radial degree of freedom and the posterior radial degree of freedom may each include: x-direction degrees of freedom and Y-direction degrees of freedom.

The redundant sensor with X-direction freedom degree can comprise: an X + direction sensor 41, and an X-direction sensor 42. A redundant sensor for Y-direction degrees of freedom, may comprise: a Y + direction sensor 43, and a Y-direction sensor 44.

For example: the radial sensor arrangement of the sensor system is shown in fig. 1, with two sensors in each degree of freedom, X +, X-and Y +, Y-, respectively, and the radial direction is divided into a front radial direction and a back radial direction. Therefore, there are 8 sensors with 4 degrees of freedom in the radial direction.

In an alternative specific example, the axial degrees of freedom may include: z-direction freedom.

Wherein, redundant sensor of Z degree of freedom includes: a Z + direction sensor 45, and a Z-direction sensor 46.

For example: axial sensors as shown in fig. 2, the sensors are arranged axially in front of and behind, and there are two sensors, Z +, Z-.

From this, set up two sensors respectively through 5 degrees of freedom to the bearing, and two sensors sharing an AD sampling channel, can guarantee the precision and the reliability that obtain the displacement signal of bearing on the one hand, and AD sampling channel can be saved to on the other hand, and then saves the resource and occupies the volume, reduces the energy consumption.

In an optional example, the control mechanism, provided for each degree of freedom, may be configured to control an operation condition of the degree of freedom to which the displacement signal belongs based on the displacement signal obtained redundantly.

Wherein, the control mechanism on each degree of freedom can only control the running condition of the degree of freedom. The running condition of the unit to which the bearing 1 belongs can be controlled by controlling the running condition of each freedom degree by each control mechanism of each freedom degree.

Therefore, the redundant sensor is used for redundantly acquiring the displacement signal of each degree of freedom, and the control mechanism is used for controlling the running condition of the unit to which the bearing belongs on the basis of the redundantly acquired displacement signal, so that the resources of the system to which the unit belongs are saved, and the reliability of controlling the running condition of the unit is improved.

Optionally, the control mechanism may include: a differential circuit 6, a selection circuit and a controller 9.

The following describes in detail the initial process of the control mechanism controlling the operation of the unit to which the bearing 1 belongs, with reference to the difference circuit 6, the selection circuit and the controller 9.

In an alternative specific example, the differential circuit 6 may be configured to perform differential processing on the displacement signal obtained redundantly to obtain a differential signal.

In an alternative specific example, the selection circuit may be configured to turn on the switch channel corresponding to the differential signal in an initial state under the control of the controller, so as to input the differential signal as an initial input signal to the controller.

In an alternative embodiment, the controller 9 may be configured to determine whether the initial input signal satisfies a first normal value for the corresponding switch channel setting. And if the initial input signal meets the first normal value, controlling the unit to operate by using an initial setting program.

For example: the controller has 3 enable signals corresponding to 3 paths of input of the selector switch, and in an initial state, the controller enables a third channel of the selector switch, the selector switch sends a differential circuit signal to the AD sampling port, and the controller samples the data through the AD port (namely the AD sampling port) and judges whether the sampled data is normal.

For example: if the data of the third channel is normal, the controller operates with an initial program to realize the normal operation of the whole controller. When determining whether the third channel data is normal, a range of normal data may be set in the program, within which range it is determined to be normal, and beyond which range it is determined to be abnormal.

Therefore, through the adaptive arrangement of the differential circuit, the selection circuit and the controller, the displacement signals obtained by redundancy can be subjected to preliminary processing, the preliminary control on the running condition of the unit to which the bearing belongs is realized, the kernel resources of the system to which the unit belongs are reduced, the system energy consumption is low, and the reliability is high.

Further, the following describes a further process of controlling the operation condition of the unit to which the bearing 1 belongs by the control mechanism in combination with the selection circuit and the controller 9.

In an optional specific example, the selection circuit may be further configured to turn on any one of switch channels corresponding to the redundantly obtained displacement signals when the initial input signal does not satisfy the first normal value, so as to input any one of the redundantly obtained displacement signals as a second input signal to the controller.

In an alternative specific example, the controller 9 may be further configured to determine whether the second input signal satisfies a second normal value set by a corresponding switch channel if the initial input signal does not satisfy the first normal value. And if the second input signal meets the second normal value, the initial setting program is switched to a second setting program corresponding to the corresponding switch channel to control the unit to operate.

For example: if the data of the third channel is abnormal, the controller enables the first channel of the selection switch, the selection switch sends the signal of the first signal conditioning circuit to the AD sampling port, the controller samples the data through the AD port, and whether the sampled data is normal is judged again. The manner of judging whether the sampled data is normal again may be the same as the manner of judging whether the data is normal for the first time.

For example: and if the first channel data is normal, the controller is switched to a corresponding program to realize the normal operation of the controller. And judging whether the first channel data is normal or not, and judging whether the first channel data is in a normal data range or not.

Therefore, through the adaptive setting of the selection circuit and the controller, the operation condition of the unit to which the bearing belongs can be further controlled based on the primary processing result of the redundantly obtained displacement signal, so that the operation reliability and safety of the system to which the unit belongs are further improved.

Further, the following describes a further process of controlling the operation condition of the unit to which the bearing 1 belongs by the control mechanism with reference to the selection circuit and the controller 9.

In an optional specific example, the selection circuit may be further configured to turn on another switch channel of the switch channels corresponding to the redundantly obtained displacement signals when the second input signal does not satisfy the second normal value, so as to use another signal of the redundantly obtained displacement signals as a third input signal to the controller.

And analogizing in sequence until all the paths of signals corresponding to the displacement signals redundantly acquired on the degrees of freedom of the displacement signals are input into the controller as corresponding input signals.

In an alternative specific example, the controller 9 may be further configured to determine whether the third input signal satisfies a third normal value set by a corresponding switch channel if the second input signal does not satisfy the second normal value. And if the third input signal meets the third normal value, the second setting program is switched to a third setting program corresponding to the corresponding switch channel to control the unit to operate.

And the rest is repeated until all the input signals on the degree of freedom of the input signals meet the corresponding normal values of the corresponding switch channels.

For example: and if the data of the first channel is abnormal, enabling the second channel of the selection switch by the controller, sending the signal of the second signal conditioning circuit to the AD sampling port by the selection switch, sampling the data by the controller through the AD port, and judging whether the sampled data is normal again.

For example: and if the second channel data is normal, the controller is switched to a corresponding program to realize the normal operation of the controller. And judging whether the second channel data is normal or not, wherein the judgment can be carried out by judging whether the second channel data is in a normal data range or not.

For example: when the third channel data is abnormal, whether the first channel data is normal or not is judged first, or whether the second channel data is normal or not is judged first. The judgment sequence of the first channel and the second channel has no influence, but only one program can be set, the first channel can be judged firstly, and the second channel can be judged firstly.

Therefore, through the adaptive setting of the selection circuit and the controller, the further processing of the displacement signal obtained through redundancy can be carried out on the basis of the further processing result, the further control of the operation condition of the unit to which the bearing belongs is realized, and the operation reliability of the system to which the unit belongs is improved better and more safely.

More alternatively, based on the above specific description of the control mechanism controlling the operation condition of the unit to which the bearing 1 belongs, a further process of the control mechanism controlling the operation condition of the unit to which the bearing 1 belongs is described in detail below.

In an optional specific example, the controller 9 in any one degree of freedom may be further configured to control the unit to stop and initiate a first warning signal of the unit failure if the initial input signal in any one degree of freedom does not satisfy the first normal value and each path of signal in the displacement signal redundantly acquired in the degree of freedom does not satisfy a corresponding normal value set by a corresponding switch channel.

For example: if the first channel is abnormal, and meanwhile, the data of the second channel is abnormal, namely, the unit reports a fault, and the normal operation cannot be realized.

For example: the Y direction and Z direction are also processed as described above.

For example: the processing sequence in the X direction, the Y direction, and the Z direction may be processed in a certain order or may be processed in any order as long as the three are processed. For example: in any direction, if the first channel signal, the second channel signal and the third channel signal (i.e. the differential signal) are abnormal, the fault of the unit is reported.

In an optional specific example, the controller 9 in any one degree of freedom may be further configured to control the unit to continue to operate and initiate a second warning signal that the initial input signal in the corresponding degree of freedom does not satisfy the first normal value if the initial input signal in any one degree of freedom does not satisfy the first normal value but at least one of the paths of signals in the displacement signals redundantly acquired in all degrees of freedom satisfies a corresponding normal value set by a corresponding switch channel.

For example: and if the third channel signal (namely the differential signal) is abnormal, the unit still continues to operate, but a warning signal is sent out.

Therefore, the alarm is given through the processing result of the displacement signal obtained based on redundancy, and the operation condition of the unit to which the bearing belongs is timely reminded, so that the reliability and the safety of the operation of the unit to which the bearing belongs are favorably improved, and the humanization is good.

Optionally, the control mechanism may further include: a signal conditioning circuit.

In an alternative embodiment, the number of signal conditioning circuits is the same as the number of redundant sensors. For example: when the number of redundant sensors is two, the number of signal conditioning circuits is also two, and the two signal conditioning circuits may include: a first signal conditioning circuit 51 and a second signal conditioning circuit 52.

For example: the first signal conditioning circuit and the second signal conditioning circuit carry out differential amplification on hardware, and the result is output to the selector switch through a third channel. The signal conditioning circuit performs filtering and amplification, and then performs differential amplification, wherein the amplification is operation of an operational amplifier, and the amplification is called amplification as long as the signal conditioning circuit passes through the operational amplifier. The difference is mainly made after filtering and amplification, but the difference is made by an operational amplifier when the difference is made.

In an optional specific example, each of the signal conditioning circuits may be configured to perform at least one of filtering and amplifying on a corresponding one of the redundantly obtained displacement signals, and then transmit the processed signal to at least one of the differential circuit 6 and the selection circuit.

For example: taking the radial direction X as an example, firstly, the eddy current sensor obtains displacement signals in the X + and X-directions, and then the two displacement signals are filtered and amplified by two signal conditioning circuits (namely a first signal conditioning circuit and a second signal conditioning circuit), at this time, the first signal conditioning circuit outputs one path of signal to the differential circuit, and outputs one path of signal to the selector switch through the first channel; similarly, the second signal conditioning circuit outputs one signal to the differential circuit and outputs the other signal to the selector switch through the second channel.

Therefore, through the adaptive setting of the signal conditioning circuit, the signal conditioning processing can be carried out on the displacement signals obtained redundantly, the accuracy and the reliability of the control over the running condition of the unit to which the bearing belongs are improved, and the control is convenient and simple.

More optionally, when the sensor may comprise an eddy current sensor, each of the signal conditioning circuits may comprise: a filter circuit, and/or a pre-set circuit of the eddy current sensor.

For example: the signal is necessarily conditioned by a signal conditioning, and the specific structure is a pre-set circuit and a filter circuit of the eddy current sensor.

Therefore, through the adaptive arrangement of the pre-processor circuit and the filter circuit, the signal conditioning processing is carried out on the redundantly acquired displacement signals, the circuit structure is simple, the processing mode is simple and convenient, and the accuracy of the processing result is good and the reliability is high.

Optionally, the differential circuit 6 may be further configured to amplify the differential signal.

Therefore, the differential signal is amplified, convenience and accuracy of subsequent processing can be improved, and reliability is high.

Optionally, the selection circuit may include: a selection switch 7 and an AD sampling channel 8.

For example: as shown in fig. 3, each degree of freedom includes two eddy current sensors, two signal conditioning circuits, a differential circuit, a selection switch, an AD sample, and a controller.

In an alternative specific example, the selection switch 7 may be configured to turn on one signal from the displacement signal obtained redundantly and the corresponding switch channel of the differential signal.

For example: the selector switch has 3 inputs: the first path is the output of the first signal conditioning circuit, namely a first channel; the second path is the output of the second signal conditioning circuit, namely a second channel; the third path is the differential circuit output, i.e., the third path.

For example: the selection switch can only select the input signal of one channel at the same time.

In an optional specific example, the AD sampling channel 8 may be configured to enable the controller 9 to sample one signal from one switch channel where the selection switch 7 is turned on.

From this, through the adaptation setting of selection switch and AD sampling channel, can promote the security and the accurate nature of signal selection and sampling.

Through a large number of tests, the technical scheme of the embodiment is adopted, and through the redundancy design, the reliability of the magnetic suspension system is improved, the resources occupied by the CPU kernel are reduced, and the number of the required AD channels is reduced.

According to the embodiment of the invention, a magnetic suspension bearing corresponding to the displacement detection device is also provided. The magnetic bearing may include: the displacement detecting device described above.

In an alternative embodiment, the radial sensor arrangement of the sensor system of the present invention is shown in FIG. 1, with two sensors in each degree of freedom, X +, X-and Y +, Y-, respectively, and with the radial directions being the forward and aft radial directions. Therefore, there are 8 sensors with 4 degrees of freedom in the radial direction. Axial sensors as shown in fig. 2, the sensors are arranged axially in front of and behind, and there are two sensors, Z +, Z-.

The radial direction refers to a direction perpendicular to the axial direction, and as shown in fig. 1, the front and the rear directions are defined to be distinguished. As shown in FIG. 2, the near Z + direction is defined as front and the near Z-direction is defined as back.

In an alternative example, the sensor is spaced apart from the shaft (i.e., not in contact with the shaft).

Optionally, the distance between the sensor and the shaft, which is correspondingly limited, can be set according to actual needs. For example: typically, eddy current sensors are relatively short in distance. For example, the distance between the eddy current sensor and the shaft can be set to be between 15um and 50um, and of course, the distance can also be set according to actual needs.

In an alternative embodiment, the overall framework of the present invention is shown in fig. 3, and each degree of freedom includes two eddy current sensors, two signal conditioning circuits, a differential circuit, a selection switch, an AD sample, and a controller.

In an optional example, taking the radial direction X as an example, firstly, the eddy current sensor obtains displacement signals in the X + and X-directions, and then the two displacement signals are filtered and amplified by two signal conditioning circuits (i.e. a first signal conditioning circuit and a second signal conditioning circuit) respectively, at this time, the first signal conditioning circuit outputs one path of signal to the differential circuit, and outputs one path of signal to the selector switch through the first channel; similarly, the second signal conditioning circuit outputs one signal to the differential circuit and outputs the other signal to the selector switch through the second channel. The signal is necessarily conditioned by a signal conditioning, and the specific structure is a pre-amplifier circuit and a filter circuit of the eddy current sensor.

The first signal conditioning circuit and the second signal conditioning circuit carry out differential amplification on hardware, and the result is output to the selector switch through a third channel. The signal conditioning circuit performs filtering and amplification, and then performs differential amplification, wherein the amplification is operation of an operational amplifier, and the amplification is called amplification as long as the signal conditioning circuit passes through the operational amplifier. The difference is mainly made after filtering and amplification, but the difference is made by an operational amplifier when the difference is made.

At this time, the selector switch has 3 inputs: the first path is the output of the first signal conditioning circuit, namely a first channel; the second path is the output of the second signal conditioning circuit, namely a second channel; the third path is the differential circuit output, i.e., the third path.

The selection switch can only select the input signal of one channel at the same time.

In an alternative example, the controller has 3 enable signals corresponding to 3 inputs of the selector switch, and in an initial state, the controller enables the third channel of the selector switch, then the selector switch sends a differential circuit signal to the AD sampling port, and the controller samples the data through the AD port (i.e., the AD sampling port) to determine whether the sampled data is normal.

Optionally, if the data of the third channel is normal, the controller operates with an initial program to realize normal operation of the whole controller. For example: when the third channel is normal, the controller controls by using the result of the differential signal as a position signal according to an initially set program.

When determining whether the third channel data is normal, a range of normal data may be set in the program, within which range it is determined to be normal, and beyond which range it is determined to be abnormal.

Optionally, if the data of the third channel is abnormal, the controller enables the first channel of the selection switch, the selection switch sends the signal of the first signal conditioning circuit to the AD sampling port, the controller samples the data through the AD port, and whether the sampled data is normal is judged again.

The manner of judging whether the sampled data is normal again may be the same as the manner of judging whether the data is normal for the first time.

At this time, if the first channel data is normal, the controller switches to the corresponding program to realize the normal operation of the controller. For example: when the first channel is normal, the controller switches to the program operation which takes the result of the first channel as the position signal for control.

And judging whether the first channel data is normal or not, and judging whether the first channel data is in a normal data range or not.

Optionally, if the data of the first channel is abnormal, the controller enables the second channel of the selection switch, the selection switch sends the signal of the second signal conditioning circuit to the AD sampling port, and the controller samples the data through the AD port and determines whether the sampled data is normal again.

Optionally, if the second channel data is normal, the controller switches to a corresponding program to realize normal operation of the controller. For example: when the second channel is normal, the controller switches to the program operation which takes the result of the second channel as the position signal for control.

And judging whether the second channel data is normal or not, wherein the judgment can be carried out by judging whether the second channel data is in a normal data range or not.

Optionally, if the first channel is abnormal, and at the same time, the data of the second channel is abnormal, that is, the unit reports a fault, and the normal operation cannot be performed.

It should be noted that, when the third channel data is abnormal, it is only necessary to first determine whether the first channel data is normal or first determine whether the second channel data is normal. The judgment sequence of the first channel and the second channel has no influence, but only one program can be set, the first channel can be judged firstly, and the second channel can be judged firstly.

Therefore, the scheme of the invention provides a redundancy design method for displacement detection, and at least can achieve the following beneficial effects:

⑴ the reliability of the system is improved, the occupied CPU kernel resource is reduced, and the required AD channel is reduced.

In the redundant design, two sensors work simultaneously in each direction under a normal working state, for example, two X + and X-sensors work in the X direction, and if one of the sensors fails, one sensor can be used for continuous operation through a program. Redundancy is designed to improve reliability, for example: if one sensor fails, the system can continue to operate normally, so that the reliability is improved.

⑴ compared with the existing redundancy method, the CPU kernel occupies less resources, and the number of displacement AD channels is reduced by 50%.

In an alternative example, the processing is also performed for the Y direction and the Z direction as described above.

The processing sequence in the X direction, the Y direction, and the Z direction may be processed in a certain order or in any order, and the three may be processed.

After the three are processed, if the first channel signal, the second channel signal and the third channel signal (namely the differential signal) are abnormal in any direction, the fault of the unit is reported; and if the third channel signal (namely the differential signal) is abnormal, the unit still continues to operate, but a warning signal is sent out.

In conclusion, the scheme of the invention adopts the redundancy design method, thereby improving the reliability of the magnetic suspension system, reducing the resources occupied by the CPU kernel and reducing the number of the required AD channels. Compared with the traditional magnetic suspension system, the scheme of the invention improves the reliability of the system; compared with the existing redundancy method, the method reduces the resource occupied by the CPU kernel and reduces the number of the displacement AD channels by 50 percent.

Wherein, the former proposal is 10 AD channels, and only 5 AD channels are needed in total, thereby reducing the number of AD channels; the original difference algorithm is software operation and needs to occupy CPU kernel resources, and the difference algorithm is realized by a hardware circuit at present and does not need to occupy the CPU kernel resources, so that the CPU kernel occupied resources are reduced.

Since the processing and functions of the magnetic suspension bearing of this embodiment are basically corresponding to the embodiments, principles and examples of the displacement detection device shown in fig. 1 to 3, the description of this embodiment is not detailed, and reference may be made to the related description in the foregoing embodiments, which is not repeated herein.

Through a large number of tests, the technical scheme of the invention is adopted, and only 5 AD channels are needed in total by arranging two sensors in each degree of freedom, so that the number of the AD channels is reduced.

According to the embodiment of the invention, a displacement detection method of the magnetic suspension bearing corresponding to the magnetic suspension bearing is also provided. The displacement detection method of the magnetic suspension bearing can comprise the following steps: the collection step comprises: redundantly acquiring displacement signals of the bearing 1 in the degree of freedom to which the displacement signals belong; the control steps are as follows: and controlling the operation condition of the degree of freedom to which the displacement signal belongs based on the redundantly obtained displacement signal.

The specific procedure of the control step is specifically described below.

In an alternative example, the difference processing step: and carrying out differential processing on the displacement signals obtained in the redundant mode to obtain differential signals.

Optionally, the differential processing step may further include: and amplifying the differential signal.

In an alternative example, the signal gating step: and switching on the switch channel corresponding to the differential signal in an initial state so as to take the differential signal as an initial input signal.

Alternatively, the signal gating step may further include: and when the initial input signal does not meet the first normal value, switching on any one of switch channels corresponding to the displacement signals obtained redundantly so as to take any one of the displacement signals obtained redundantly as a second input signal.

Alternatively, the signal gating step may further include: and when the second input signal does not meet the second normal value, switching on another switch channel in the switch channels corresponding to the displacement signals obtained redundantly so as to take another path of signals in the displacement signals obtained redundantly as a third input signal.

And analogizing in sequence until all the paths of signals corresponding to the displacement signals redundantly acquired on the degrees of freedom of the displacement signals are input as corresponding input signals.

Optionally, the signal gating step may further include: switching on a signal in the corresponding switch channel of the displacement signal and the differential signal obtained by self redundancy; and sampling the signal from the switched-on switch channel.

In an alternative example, the signal processing step: it is determined whether the initial input signal satisfies a first normal value set for the corresponding switch channel. And if the initial input signal meets the first normal value, controlling the unit to operate by using an initial setting program.

Alternatively, the signal processing step may further include: and if the initial input signal does not meet the first normal value, determining whether the second input signal meets a second normal value set by a corresponding switch channel. And if the second input signal meets the second normal value, the initial setting program is switched to a second setting program corresponding to the corresponding switch channel to control the unit to operate.

Alternatively, the signal processing step may further include: and if the second input signal does not meet the second normal value, determining whether the third input signal meets a third normal value set by a corresponding switch channel. And if the third input signal meets the third normal value, the second setting program is switched to a third setting program corresponding to the corresponding switch channel to control the unit to operate.

Therefore, the control of the running condition of the unit to which the bearing belongs is realized by processing the displacement signals obtained by redundancy, the kernel resource of the system to which the unit belongs is reduced, the system energy consumption is low, and the reliability is high.

In an optional example, the controlling step may further include: initiating a warning step: and if the initial input signal on any one degree of freedom does not meet the first normal value and each path of signal in the displacement signal redundantly acquired on the degree of freedom does not meet the corresponding normal value set by the corresponding switch channel, controlling the unit to stop and starting a first warning signal of the unit fault.

Or, in the step of initiating the warning, the method may further include: and if the initial input signal on any degree of freedom does not meet the first normal value, but at least one of the signals in the displacement signals obtained redundantly on all degrees of freedom meets the corresponding normal value set by the corresponding switch channel, controlling the unit to continue to operate, and initiating a second warning signal that the initial input signal on the corresponding degree of freedom does not meet the first normal value.

In an optional example, the controlling step may further include: signal conditioning step: and carrying out at least one of filtering and amplifying on corresponding path signals in the displacement signals obtained redundantly, and then carrying out at least one of differential processing and signal gating processing.

Since the processing and functions implemented by the displacement detection method of this embodiment substantially correspond to the embodiments, principles, and examples of the magnetic suspension bearing, the description of this embodiment is not given in detail, and reference may be made to the related descriptions in the embodiments, which are not repeated herein.

A large number of tests prove that by adopting the technical scheme of the invention, the differential processing is carried out through the hardware circuit, and the CPU kernel resource is not occupied, so that the CPU kernel resource occupation is reduced.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A displacement detecting device, comprising: redundant sensors and control mechanisms; wherein the content of the first and second substances,

the redundant sensor is arranged on each degree of freedom of the bearing (1) to be detected and used for redundantly acquiring displacement signals of the bearing (1) on the degree of freedom; by placing two sensors in each degree of freedom, only 5 AD channels are needed in total;

the control mechanism is used for controlling the operation condition of the degree of freedom to which the displacement signal belongs based on the displacement signal obtained in a redundant manner;

the control mechanism includes: a differential circuit (6), a selection circuit and a controller (9); wherein, the control mechanism controls the running condition of the unit to which the bearing (1) belongs, and comprises:

the differential circuit (6) is used for carrying out differential processing on the displacement signals obtained in a redundant mode to obtain differential signals;

the selection circuit is used for switching on the switch channels corresponding to the differential signals in an initial state under the control of the controller so as to input the differential signals to the controller as initial input signals; the selection circuit includes: a selection switch (7) and an AD sampling channel (8); the selection switch (7) is used for switching on a path of signal in the displacement signal obtained by self redundancy and the corresponding switch channel of the differential signal; the AD sampling channel (8) is used for enabling the controller (9) to sample the signal from one switch channel which is switched on by the selection switch (7);

the controller (9) is used for determining whether the initial input signal meets a first normal value set by a corresponding switch channel; if the initial input signal meets the first normal value, controlling the unit to operate by an initial setting program;

differential processing is carried out through a hardware circuit, and CPU kernel resources are not occupied;

the control mechanism controls the running condition of the unit to which the bearing (1) belongs, and further comprises:

the selection circuit is further configured to switch on any one of switch channels corresponding to the displacement signals obtained redundantly when the initial input signal does not meet the first normal value, so that any one of the displacement signals obtained redundantly is input to the controller as a second input signal;

the controller (9) is further configured to determine whether the second input signal satisfies a second normal value set for a corresponding switch channel if the initial input signal does not satisfy the first normal value; if the second input signal meets the second normal value, the initial setting program is switched to a second setting program corresponding to the corresponding switch channel to control the unit to operate; through the adaptive arrangement of the differential circuit, the selection circuit and the controller, the displacement signals obtained redundantly can be subjected to preliminary processing, the preliminary control over the running condition of the unit to which the bearing belongs is realized, and the kernel resources of the system to which the unit belongs are reduced.

2. The apparatus of claim 1, wherein,

the redundant sensor, comprising: two sensors; the two sensors are symmetrically arranged at two ends of each degree of freedom of the bearing (1);

and/or the presence of a gas in the gas,

each sensor is arranged at a distance from the shaft (3) of the bearing (1).

3. The apparatus of claim 1 or 2, wherein,

each of the sensors, comprising: an eddy current sensor;

and/or the presence of a gas in the gas,

the bearing (1) comprises: a magnetic suspension bearing;

and/or the presence of a gas in the gas,

an air gap (2) is arranged between the bearing (1) and the shaft (3) of the bearing.

4. The apparatus of claim 1 or 2, wherein the degrees of freedom in which the redundant sensor is provided comprise: a radial degree of freedom and/or an axial degree of freedom; wherein the content of the first and second substances,

the radial degree of freedom includes: a front radial degree of freedom and a rear radial degree of freedom respectively distributed forward and backward with respect to the axial degree of freedom; the anterior radial degree of freedom and the posterior radial degree of freedom each include: an X-direction degree of freedom and a Y-direction degree of freedom;

the axial degree of freedom includes: z-direction freedom.

5. The apparatus of claim 3, wherein the degrees of freedom in which the redundant sensor is disposed comprise: a radial degree of freedom and/or an axial degree of freedom; wherein the content of the first and second substances,

the axial degree of freedom includes: z-direction freedom.

6. The device according to claim 1, wherein the control mechanism controls the operation of the unit to which the bearing (1) belongs, and further comprises:

the selection circuit is further configured to switch on another switch channel in the switch channels corresponding to the displacement signals obtained redundantly when the second input signal does not meet the second normal value, so as to use another path of signals in the displacement signals obtained redundantly as a third input signal to the controller;

repeating the operation until all paths of signals corresponding to the displacement signals redundantly acquired in the degree of freedom of the controller are input into the controller as corresponding input signals;

the controller (9) is further configured to determine whether the third input signal satisfies a third normal value set by a corresponding switch channel if the second input signal does not satisfy the second normal value; if the third input signal meets the third normal value, the second setting program is switched to a third setting program corresponding to the corresponding switch channel to control the unit to operate;

7. The device according to claim 1 or 6, wherein the control mechanism controls the operation of the unit to which the bearing (1) belongs, and further comprises:

the controller (9) is further configured to control the unit to stop and initiate a first warning signal of the unit failure if the initial input signal in any one degree of freedom does not meet the first normal value and each path of signal in the displacement signal redundantly acquired in the degree of freedom does not meet a corresponding normal value set by a corresponding switch channel;

or if the initial input signal on any degree of freedom does not meet the first normal value, but at least one path of signals in the displacement signals obtained redundantly on all degrees of freedom meets the corresponding normal value set by the corresponding switch channel, controlling the unit to continue to operate, and initiating a second warning signal that the initial input signal on the corresponding degree of freedom does not meet the first normal value.

8. The device of claim 1 or 6, wherein the control mechanism further comprises: a signal conditioning circuit;

the number of the signal conditioning circuits is the same as that of the redundant sensors; each signal conditioning circuit is used for processing at least one of filtering and amplifying corresponding path signals in the redundantly obtained displacement signals and then transmitting the processed signals to the differential circuit (6);

the differential circuit (6) is also used for amplifying the differential signal.

9. The apparatus of claim 7, wherein the control mechanism further comprises: a signal conditioning circuit;

10. The apparatus of claim 8, wherein when the sensor comprises an eddy current sensor, each of the signal conditioning circuits comprises: a filter circuit, and/or a pre-set circuit of the eddy current sensor.

11. The apparatus of claim 9, wherein when the sensor comprises an eddy current sensor, each of the signal conditioning circuits comprises: a filter circuit, and/or a pre-set circuit of the eddy current sensor.

12. A magnetic bearing, comprising: a displacement detecting device according to any one of claims 1-11.

13. A method of detecting the displacement of a magnetic bearing as claimed in claim 12, comprising:

the collection step comprises: redundantly acquiring displacement signals of the bearing (1) in the degree of freedom to which the displacement signals belong; by placing two sensors in each degree of freedom, only 5 AD channels are needed in total;

the control steps are as follows: controlling the operation condition of the degree of freedom to which the displacement signal belongs based on the displacement signal obtained in a redundant manner;

the control step includes:

a difference processing step: carrying out differential processing on the displacement signals obtained in a redundant mode to obtain differential signals;

a signal gating step, comprising: switching on a switch channel corresponding to the differential signal in an initial state to take the differential signal as an initial input signal; the signal gating step further includes: switching on a signal in the corresponding switch channel of the displacement signal and the differential signal obtained by self redundancy; sampling the signal from the switched-on switch channel;

the control step further includes:

signal gating step: when the initial input signal does not meet the first normal value, any one of switch channels corresponding to the displacement signals obtained redundantly is switched on, and any one of the displacement signals obtained redundantly is used as a second input signal;

when the second input signal does not meet the second normal value, switching on another switch channel in the switch channels corresponding to the displacement signals obtained in a redundant mode, and taking another path of signals in the displacement signals obtained in the redundant mode as third input signals;

repeating the operation until all paths of signals corresponding to the displacement signals which are redundantly obtained on the degrees of freedom of the operation are input as corresponding input signals; through the adaptive arrangement of the differential circuit, the selection circuit and the controller, the displacement signals obtained redundantly can be subjected to preliminary processing, the preliminary control over the running condition of the unit to which the bearing belongs is realized, and the kernel resources of the system to which the unit belongs are reduced.

14. The method of claim 13, wherein the controlling step further comprises:

a signal processing step: determining whether the initial input signal meets a first normal value set by a corresponding switch channel; if the initial input signal meets the first normal value, controlling the unit to operate by an initial setting program;

if the initial input signal does not meet the first normal value, determining whether the second input signal meets a second normal value set by a corresponding switch channel; if the second input signal meets the second normal value, the initial setting program is switched to a second setting program corresponding to the corresponding switch channel to control the unit to operate;

if the second input signal does not meet the second normal value, determining whether the third input signal meets a third normal value set by a corresponding switch channel; if the third input signal meets the third normal value, the second setting program is switched to a third setting program corresponding to the corresponding switch channel to control the unit to operate;

15. The method of claim 14, wherein the controlling step further comprises:

initiating a warning step: if the initial input signal on any one degree of freedom does not meet the first normal value and each path of signal in the displacement signal redundantly acquired on the degree of freedom does not meet the corresponding normal value set by the corresponding switch channel, controlling the unit to stop and starting a first warning signal of the unit fault;

or if the initial input signal on any degree of freedom does not meet the first normal value, but at least one path of signals in the displacement signals obtained redundantly on all degrees of freedom meets the corresponding normal value set by the corresponding switch channel, controlling the unit to continue to operate, and initiating a second warning signal that the initial input signal on the corresponding degree of freedom does not meet the first normal value;

and/or the presence of a gas in the gas,

signal conditioning step: and carrying out at least one of filtering and amplification on the corresponding path of signals in the redundantly obtained displacement signals, and then carrying out differential processing.

16. The method of claim 14 or 15, wherein,

the difference processing step further includes: and amplifying the differential signal.