Slip ring encoder, encoding method and CT equipment

Abstract

The invention provides a slip ring encoder, an encoding method and CT equipment, which can be applied to the field of encoders and CT equipment, and the slip ring encoder comprises an encoding band which is provided with a plurality of first holes which are regularly arranged; a plurality of signal acquisition board cards which are mutually independent and are arranged at one side of the coding band, each signal acquisition board card comprises a first signal sensor, and the first signal sensor is configured to generate a first acquisition signal according to light which is emitted from the other side of the coding band and penetrates through the plurality of first holes when rotating relative to the coding band; and the signal processing board card is electrically connected to the plurality of signal acquisition board cards and is configured to generate a first coded signal based on at least one of the plurality of first acquisition signals. The method has the advantages that the problem of simultaneous failure of the coding signals caused by continuous hole blocking of the coding band can be solved, and the probability of loss of the coding band trigger signals caused by local continuous hole blocking of the coding band is reduced.

Description

Technical Field

[0001] The present disclosure relates to the fields of encoders and CT devices, and particularly to a slip ring encoder, an encoding method, and a CT device. Background Art

[0002] A CT (Computed Tomography) device generally uses a precisely collimated X-ray beam, γ-ray, ultrasonic wave, etc., together with a highly sensitive detector, to perform successive cross-sectional scans around a certain part of the human body. After being processed by a computer, a three-dimensional image of this part is generated. Currently, one method for measuring the rotational speed of a slip ring on a similar CT device is to use a slip ring coding tape and a photoelectric sensor for speed measurement, and another method is to use a proximity switch for speed measurement. The speed measurement of the slip ring coding tape has relatively high real-time performance. When the slip ring rotates at a high speed, the signal output time reaches the order of hundreds of microseconds, and it can well detect the instantaneous speed of the slip ring.

[0003] Existing coding tapes may have problems of blocked holes. Once there are blocked holes on the coding tape, it will cause inaccurate rotational speed measurement, thereby affecting the position information of data acquisition binding, and ultimately affecting the image. The prior art usually sets paired photoelectric sensors on a detection module as redundant detections. The two photoelectric sensors are on the same circuit board. After continuous multiple hole positions are blocked due to dust accumulation or grease contamination on the coding tape, the signals of the two photoelectric sensors will fail simultaneously, easily resulting in the loss of output pulse signals. Summary of the Invention

[0004] In view of the above problems, the present disclosure provides a slip ring encoder, an encoding method, and a CT device that can effectively prevent the encoder from failing due to continuous blocked holes. The present disclosure reduces the probability of signal loss in the coding tape acquisition caused by local continuous blocked holes in the coding tape by using multiple signal acquisition boards to detect the signals of the coding tape.

[0005] According to a first aspect of the present disclosure, there is provided a slip ring encoder, including: a coding tape having a plurality of first type holes arranged regularly; a plurality of mutually independent signal acquisition boards arranged on one side of the coding tape, each signal acquisition board including a first signal sensor configured to generate a first acquisition signal according to the light emitted from the other side of the coding tape and passing through the plurality of first type holes when rotating relative to the coding tape; a signal processing board electrically connected to the plurality of signal acquisition boards and configured to generate a first encoding signal based on at least one of the plurality of first acquisition signals.

[0006] According to an embodiment of the present disclosure, the plurality of signal acquisition boards are arranged on one side of the coding tape based on generating a plurality of first acquisition signals having substantially the same phase.

[0007] According to an embodiment of the present disclosure, a plurality of signal acquisition boards are separately arranged from the signal processing board.

[0008] According to an embodiment of the present disclosure, based on at least one of a plurality of first acquisition signals, a first encoded signal is generated, including: the signal processing board is configured to select one of the first acquisition signals to generate the first encoded signal; wherein, when the selected first acquisition signal is lost, other first acquisition signals are selected to generate the first encoded signal.

[0009] According to an embodiment of the present disclosure, adjacent signal acquisition boards are arranged on one side of the encoding band with a central angle interval of more than 1°.

[0010] According to an embodiment of the present disclosure, each signal acquisition board includes a second signal sensor. The second signal sensor is configured to generate a plurality of second acquisition signals according to the light emitted from the other side of the encoding band and passing through a plurality of first-type holes when rotating relative to the encoding band; based on the relative position differences between the first signal sensor, the second signal sensor and any one of the plurality of first-type holes, the first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference; the signal processing board is configured to generate a second encoded signal based on at least one of the plurality of second acquisition signals; the first encoded signal and the second encoded signal are used to determine the rotation direction of the slip ring.

[0011] According to an embodiment of the present disclosure, the preset phase difference between the first acquisition signal and the second acquisition signal generated by each signal acquisition board is between 1 / 4 and 3 / 4 of the signal period.

[0012] According to an embodiment of the present disclosure, the encoding band has second-type holes. Each signal acquisition board includes a third signal sensor. The third signal sensor is configured to generate a plurality of third acquisition signals according to the light emitted from the other side of the encoding band and passing through the second-type holes when rotating relative to the encoding band; the signal processing board is configured to generate a third encoded signal based on at least one of the plurality of third acquisition signals; the third encoded signal is used to determine the number of rotation turns of the slip ring.

[0013] Another aspect of the embodiments of the present disclosure provides an encoding method for a slip ring encoder, which is applied to the above slip ring encoder. The method includes: when a plurality of first signal sensors of a plurality of signal acquisition boards rotate relative to the encoding band, generating a plurality of first acquisition signals based on the light emitted from the other side of the encoding band and passing through a plurality of first-type holes; generating a first encoded signal based on at least one of the plurality of first acquisition signals.

[0014] According to an embodiment of the present disclosure, the method includes detecting whether the first acquisition signal is lost; and indicating the abnormal position of the encoding band based on the loss position of the first acquisition signal.

[0015] According to an embodiment of the present disclosure, generating a first encoded signal based on at least one of a plurality of first acquisition signals includes: selecting one of the first acquisition signals to generate the first encoded signal; wherein when the selected first acquisition signal is lost, selecting other first acquisition signals to generate the first encoded signal.

[0016] According to an embodiment of the present disclosure, the method includes: when a plurality of second signal sensors of a plurality of signal acquisition boards rotate relative to the encoding tape, generating a plurality of second acquisition signals according to the light emitted from the other side of the encoding tape and passing through a plurality of first type holes; generating a second encoded signal based on one of the plurality of second acquisition signals; determining the rotation direction of the slip ring based on the first encoded signal and the second encoded signal. Wherein each signal acquisition board includes a second signal sensor, and based on the relative position difference between the first signal sensor, the second signal sensor and any one of the plurality of first type holes, the first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference.

[0017] According to an embodiment of the present disclosure, the method includes: when a plurality of third signal sensors of a plurality of signal acquisition boards rotate relative to the encoding tape, generating a plurality of third acquisition signals according to the light emitted from the other side of the encoding tape and passing through second type holes; generating a third encoded signal based on at least one of the plurality of third acquisition signals; determining the number of rotation turns of the slip ring based on the third encoded signal. Wherein the encoding tape has one second type hole, and each signal acquisition board includes a third signal sensor.

[0018] According to an embodiment of the present disclosure, the method includes: accumulating the first encoded signal, and when the accumulated count value based on the first encoded signal reaches a preset value and the third encoded signal, incrementing the number of rotation turns value of the slip ring by one.

[0019] Another aspect of the embodiments of the present disclosure provides a CT device including the above-mentioned slip ring encoder.

[0020] The above one or more embodiments have the following beneficial effects:

[0021] Through the implementation of the present disclosure, by setting a plurality of mutually independent signal acquisition boards, the signal processing board is electrically connected to the plurality of signal acquisition boards for generating a first encoded signal based on at least one of the plurality of first acquisition signals. It breaks through the limitation in the encoder field that two optoelectronic sensors are on the same circuit board and the sensor pair design of signal acquisition redundancy technology. When the continuously blocked hole area of the encoding tape is large, as long as it is ensured that at any moment one signal acquisition board can normally generate a first encoded signal, the encoder can work normally. It can improve the problem that the encoded signals fail simultaneously due to continuous blocking of holes in the encoding tape, reduce the probability of loss of the encoding tape trigger signal caused by local continuous blocking of holes in the encoding tape, and extend the maintenance cycle of the encoding tape and the optoelectronic detection module.

[0022] The implementation of the present disclosure detects whether the corresponding first acquisition signal is lost based on the phase deviation, which can conveniently identify the fault location of the coding tape, give an alarm signal for the blocked hole area, and avoid blindly checking the blocked hole position of the coding tape.

[0023] In some implementations of the present disclosure, each signal acquisition board card respectively acquires the first acquisition signal A, the second acquisition signal B, and the third acquisition signal Z-phase acquisition signal. The signal processing board card generates the first coding signal, the second coding signal, and the third coding signal respectively according to the A / B / Z-phase acquisition signals of each signal acquisition board card, and finally determines the accurate rotation speed, rotation direction, and number of turns of the slip ring through processing.

[0024] In the implementation of the present disclosure, in each acquisition module, there is no need to set paired signal sensors, which reduces the probability of failure due to blocked holes, reduces the design complexity of the acquisition module, reduces the design limitations, and reduces the cost of a single acquisition module. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Through the following description of the embodiments of the present disclosure with reference to the drawings, the above content and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:

[0026] Figure 1 Schematically shows the working principle diagram of a slip ring encoder.

[0027] Figure 2 Schematically shows the speed measurement principle diagram of an existing slip ring encoder.

[0028] Figure 3 Schematically shows a slip ring encoder according to an embodiment of the present disclosure.

[0029] Figure 4 Schematically shows the acquisition signal schematic diagram of a slip ring encoder according to an embodiment of the present disclosure.

[0030] Figure 5 Schematically shows another slip ring encoder according to an embodiment of the present disclosure.

[0031] Figure 6 Schematically shows another slip ring encoder according to an embodiment of the present disclosure.

[0032] Figure 7 Schematically shows the flowchart of a coding method for a slip ring encoder according to an embodiment of the present disclosure.

[0033] Figure 8 Schematically shows the flowchart of another coding method for a slip ring encoder according to an embodiment of the present disclosure.

[0034] Figure 9Schematically shows a flowchart of another slip ring encoder encoding method according to an embodiment of the present disclosure.

[0035] Figure 10 Schematically shows a structural diagram of a CT device according to an embodiment of the present disclosure.

[0036] Figure 11 Schematically shows a partial structural diagram of a CT device according to an embodiment of the present disclosure.

[0037] In the figure: 1, encoding tape; 2, 21 - 23, signal acquisition boards; 3, 31 - 33, light-emitting devices; 4, signal processing board; 5, slip ring; 6, CT device body.

[0038] It should be noted that, for clarity, in the drawings used to describe the embodiments of the present disclosure, the dimensions of the overall / local structure or overall / local area may be enlarged or reduced, that is, these drawings are not drawn to actual scale. Detailed implementation manners

[0039] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure.

[0040] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0041] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0042] Figure 1 Shows the working principle diagram of an existing slip ring encoder. As Figure 1 and 2As shown, the slip ring encoder includes an encoder belt 1 and a signal acquisition board 2 positioned on one side of the encoder belt. The signal acquisition board 2 may use optical signal acquisition technology, for example, incorporating a photoelectric sensor. The encoder belt may be a steel belt. It is fixed to the slip ring and rotates with it. The encoder belt 1 has regularly spaced holes. A light-emitting device 3 (e.g., a light-emitting diode) is positioned on the other side of the encoder belt 1, opposite the signal acquisition board 2. The signal acquisition board 2 and the light-emitting device 3 remain stationary relative to each other. Light emitted by the light-emitting device 3 passes through the holes in the encoder belt and is detected by the signal acquisition board 2. The signal acquisition board 2 converts the collected light signal into an electrical signal with a high or low level. As the encoder belt 1 and the signal acquisition board 2 rotate relative to each other, the light beam switches on and off, converting the sensed light signal into an electrical signal or pulse related to the rotational speed, with the pulse frequency proportional to the rotational speed of the slip ring.

[0043] During extended operation, dust and other foreign matter can often cause the holes in the encoder belt 1 in the slip ring encoder to become completely or partially blocked. Because slip ring encoder belt speed measurement technology requires high signal quality, redundant sensors must maintain the same phase. Otherwise, speed and other measurement parameters will be affected.

[0044] In this field, in order to prevent the coding tape from being blocked, technicians have long been able to set two sensors together in pairs, that is, on the same sensor circuit board. When processing the sensor circuit board, the positions of the two sensors can be predetermined. The positions of the two sensors are related to the hole positions of the coding tape. The paired design and fixed position of the sensors ensure that the redundant sensors have the same phase. Figure 2 As shown, a pair of sensors are mounted on a circuit board 7 to generate two sensing signals, A1 and A2. A light-emitting device 3 is positioned opposite the sensors across the coding strip 1. The distance between these sensors is predetermined, and the two sensing signals A1 and A2 generated by the light-emitting device 3 are aligned in phase. A signal combination module 6 is also mounted on the circuit board 7 to perform an OR operation on the sensing signals A1 and A2 to generate a signal A'. This signal A' is processed by a differential module 8 and then output.

[0045] The following will be based on Figures 3 - 5 The slip ring encoder according to the embodiment of the present disclosure is described in detail.

[0046] Figure 3 A slip ring encoder according to an embodiment of the present disclosure is schematically shown.

[0047] like Figure 3 As shown, this embodiment includes:

[0048] The coding tape 1 has a plurality of first - type holes arranged regularly; a plurality of mutually independent signal acquisition board cards 21 - 23 are arranged on one side of the coding tape. Each signal acquisition board card includes a first signal sensor, and the first signal sensor is configured to generate a first acquisition signal according to the light emitted from the other side of the coding tape and passing through the plurality of first - type holes when rotating relative to the coding tape; the signal processing board card 4 is electrically connected to the plurality of signal acquisition board cards and is configured to generate a first coding signal based on at least one of the plurality of first acquisition signals. The first coding signal is used to determine the rotation speed of the slip ring.

[0049] In an embodiment of the present disclosure, the signal acquisition board card is a circuit board card including a photoelectric sensor. It can utilize the photoelectric effect. When light irradiates a photodiode, a photocurrent is formed to achieve optical signal acquisition. In an embodiment of the present disclosure, the plurality of signal acquisition board cards are independently manufactured, set, and complete signal acquisition. During the working process of the first signal sensor of each signal acquisition board card, a first acquisition signal is independently generated. Therefore, during the manufacturing process of different signal acquisition board cards, there are no restrictions on the phase and distance between the photoelectric sensors of each other. Secondly, the plurality of signal acquisition board cards are independently installed. The plurality of signal acquisition board cards are not on the same circuit board and can be arranged adjacent to or scattered on one side of the coding tape. Each signal acquisition board card independently completes signal acquisition using its own photoelectric sensor, and the first acquisition signal formed by the acquisition is further processed by the signal processing board card. In an embodiment of the present disclosure, the signal processing board card can usually be set independently of the signal acquisition board card or can be set on one of the signal acquisition board cards. Preferably, in this embodiment, the plurality of signal acquisition board cards and the signal processing board card are separated. By separating the signal acquisition board card of the slip - ring coding tape from the signal processing board card and using multiple slip - ring coding - tape signal acquisition boards to detect the coding - tape signal, the multiple slip - ring coding - tape signal acquisition boards are spaced apart on the slip ring, reducing the probability of loss of the coding - tape trigger signal caused by local continuous blockage of holes in the coding tape.

[0050] In this embodiment, during the working state, the signal acquisition board card and the coding tape will rotate relative to each other. Specifically, for example, the signal acquisition board card is fixed to the slip ring and rotates together with the slip ring, while the coding tape is fixed on the device and does not rotate with the slip ring. It can also be implemented in a way that the coding tape is fixed to the slip ring and can rotate together with the slip ring.

[0051] In this embodiment, each signal acquisition board card includes a first signal sensor. When the first signal sensor is configured to rotate relative to the encoding tape, a first acquisition signal is generated according to the light emitted from the other side of the encoding tape and passing through a plurality of first-type holes. In the normal working state, when the first signal sensors included in the signal acquisition board cards 21-23 are configured to rotate relative to the encoding tape, a plurality of first acquisition signals can be generated according to the light emitted from the other side of the encoding tape and passing through a plurality of first-type holes. For example, the first signal sensor of the signal acquisition board card 21 receives the light emitted by the light-emitting device 31 on the other side of the encoding tape 1 and passing through the holes of the encoding tape 1 to generate the first acquisition signal A1; the first signal sensor of the signal acquisition board card 22 receives the light emitted by the light-emitting device 32 on the other side of the encoding tape 1 and passing through the holes of the encoding tape 1 to generate the first acquisition signal A2; the first signal sensor of the signal acquisition board card 23 receives the light emitted by the light-emitting device 33 on the other side of the encoding tape 1 and passing through the holes of the encoding tape 1 to generate the first acquisition signal A3. It should be noted that the first acquisition signals A1, A2, and A3 are generated simultaneously in the working state. The signal processing board card 4, connected to the signal acquisition board card, is configured to generate a first encoding signal A' based on at least one of the plurality of first acquisition signals A1, A2, and A3. In the case where the encoding tape has local hole blockage, at a certain moment, when the signal acquisition board card 21 rotates to the position of the blocked hole of the encoding tape, the signal acquisition board card 21 cannot generate the first acquisition signal. At this time, the signal acquisition board cards 22 and 23 normally generate the first acquisition signal A2 and the first acquisition signal A3. At another moment, the signal acquisition board card 21 leaves the position of the blocked hole of the encoding tape, and the signal acquisition board card 22 rotates to the position of the blocked hole of the encoding tape. The signal acquisition board card 22 cannot generate the first acquisition signal. At this time, the signal acquisition board cards 21 and 23 normally generate the first acquisition signal A1 and the first acquisition signal A3. At yet another moment, the signal acquisition board card 22 leaves the position of the blocked hole of the encoding tape, and the signal acquisition board card 23 rotates to the position of the blocked hole of the encoding tape. The signal acquisition board card 23 cannot generate the first acquisition signal. At this time, the signal acquisition board cards 21 and 22 normally generate the first acquisition signal A1 and the first acquisition signal A2. Therefore, in the case where the encoding tape has local hole blockage, although different signal acquisition board cards will alternately lose the position encoding information, the other signal acquisition board cards can still work normally. When the continuously blocked hole area of the encoding tape is large, as long as it is ensured that at any moment, as long as one signal acquisition board card is normal, the first encoding signal can be generated, and the device can work normally. Generating the first encoding signal based on at least one of the plurality of first acquisition signals can be to perform an OR operation on the plurality of first acquisition signals to generate the first encoding signal, or to select one of the signals as the first encoding signal. When the selected first acquisition signal is lost, another first acquisition signal is selected as the first encoding signal. This embodiment preferably adopts the latter method for implementation, which will be further described in detail in the subsequent embodiments.

[0052] In this embodiment, due to the adoption of a design concept different from the prior art, signal detection is performed on the coding tape by using multiple signal acquisition boards. Redundant sensors may not be designed in each signal acquisition board, and it can largely avoid the simultaneous failure of coding signals caused by continuous blockage of holes in the coding tape, reducing the probability of loss of trigger signals of the coding tape caused by local continuous blockage of holes in the coding tape.

[0053] In some embodiments of the present disclosure, multiple signal acquisition boards are arranged on one side of the coding tape based on generating multiple first acquisition signals having substantially the same phase. In the general understanding in the art, signals with the same phase can be utilized as one path of signals. In this embodiment, multiple signal acquisition boards are arranged on one side of the coding tape based on generating multiple first acquisition signals having substantially the same phase, greatly reducing the difficulty of specific implementation, and making it unnecessary for multiple signal acquisition boards 21 - 23 to be processed on the same circuit board and maintain a preset fixed distance to obtain the same signal phase. In this embodiment, it is only necessary to satisfy that multiple signal acquisition boards are arranged on one side of the coding tape based on generating multiple first acquisition signals having substantially the same phase.

[0054] In this embodiment, when multiple slip ring coding tape signal acquisition boards are first installed on the slip ring, the phase edges of each signal acquisition board need to be aligned. Generally, for example, different signal acquisition boards just need to receive the light of the light emitting device through the coding tape holes. During the phase adjustment process, the signal processing board connected to the signal acquisition board will give a phase alignment indication. After the position adjustment of multiple signal acquisition boards meets the requirements, the indicator light on the signal processing board will light up. Since the signal acquisition boards are installed on the slip ring later at this time, although the indicator light on the signal processing board will light up, the multiple first acquisition signals generated by the signal acquisition boards may still have phase deviations. That is, multiple signal acquisition boards generate multiple first acquisition signals having substantially the same phase.

[0055] In some embodiments of the present disclosure, generating a first coding signal based on at least one of the multiple first acquisition signals includes: the signal processing board is configured to select one path of the first acquisition signals to generate the first coding signal; wherein, when the selected first acquisition signal is lost, select other paths of the first acquisition signals to generate the first coding signal.

[0056] In this embodiment, since the signal acquisition board is arranged on one side of the coding tape based on generating multiple first acquisition signals with substantially the same phase, there may still be a certain phase deviation between the first acquisition signals generated by different signal acquisition boards. There are certain drawbacks to the method of directly OR-ing different first acquisition signals to generate the first coding signal. Especially when these phase deviations are large to a certain extent, OR-ing different first acquisition signals to generate the first coding signal does not meet the usage conditions, and even the duty cycle may reach 100%. Although the phases of different signal acquisition boards are aligned during the installation of the signal acquisition module, due to factors such as mechanical vibration, signals, and rotational speed during use, the phase deviation between different signal acquisition modules may gradually increase, and the duty cycle of OR-ing different first acquisition signals to generate the first coding signal may reach 100%, ultimately resulting in the unavailability of OR-ing different first acquisition signals to generate the first coding signal. This embodiment adopts the method of monitoring the first acquisition signals generated by multiple signal acquisition boards and selecting one of the first acquisition signals to generate the first coding signal. When the selected first acquisition signal is lost, other first acquisition signals are selected to generate the first coding signal. Even if there are large phase deviations between the first acquisition signals of multiple signal acquisition boards, since only one first acquisition signal is selected to follow under normal circumstances, the output waveform is normal. If a hole is blocked, when selecting to follow other first acquisition signals to generate the first coding signal, only the waveform will be distorted when switching to follow other first acquisition signals, and there will be no situation where the signal duty cycle reaches 100% or other conditions that affect signal reading.

[0057] As Figure 4 shown, the signal processing board 4 is configured to monitor the first acquisition signals A1, A2, and A3 generated by the signal acquisition boards 21 - 23 and select one of the first acquisition signals A1 to generate the first coding signal A'. When the signal acquisition board 21 runs to the position where the coding tape has a blocked hole and the selected first acquisition signal A1 is lost when a pulse signal is expected to be generated, the signal processing board 4 selects the first acquisition signal A2 generated by the signal acquisition board 22 to continue generating the first coding signal A'. Similarly, when the signal acquisition board 22 runs to the position where the coding tape has a blocked hole and the selected first acquisition signal A2 is lost when a pulse signal is expected to be generated, the signal processing board 4 selects the first acquisition signal A3 of the signal acquisition board 23 again to continue generating the first coding signal A'. Since the pulse frequency of the first coding signal A' is proportional to the rotational speed of the slip ring, the rotational speed of the corresponding slip ring can be further obtained based on the first coding signal A'. For example, if the coding tape has n holes and the slip ring rotates one week with a total of n pulses, at a rotational speed of r revolutions per minute of the slip ring, r * n / 60 pulses will be generated per second, and the signal period = 1 / f = 60 / (r * n). The real-time rotational speed of the slip ring can be obtained based on the pulse frequency.

[0058] In some embodiments, adjacent signal acquisition boards are arranged on one side of the coding tape with a central angle interval of more than 1°. Since the coding tape usually has thousands of regularly arranged holes, for example, the central angle between adjacent holes on some coding tapes is 0.25°. The adjacent signal acquisition boards are arranged on one side of the coding tape with a central angle interval of more than 1°. Theoretically, as long as the continuous blocked hole area is less than a certain designed angle w (where w is 360° minus the largest angle among the intervals between adjacent signal acquisition boards), the encoder can work properly. In one embodiment, for example, when a slip ring encoder is provided with 3 signal acquisition boards, the central angle between adjacent signal acquisition boards can be more than 10°. In this case, the central angle intervals between the 3 signal acquisition boards are 10°, 175°, and 175° respectively. In this situation, the largest angle among the intervals between adjacent signal acquisition boards is 175°. As long as the continuous blocked holes are less than 185° (185° = 360° - 175°), the normal operation of the signal acquisition boards can be ensured.

[0059] Since different spacing distances correspond to different circumferential angles, for the convenience of description, this embodiment can be described in terms of a certain distance apart, and the essence is the same. The distance mentioned in this embodiment refers to the distance along the arc of the coding tape, rather than the straight-line distance. As Figure 3 shown, in this embodiment, since the coding tape is annular, a plurality of signal acquisition boards 21-23 are distributed along the circumferential direction of the annular coding tape, and there is a distance d between adjacent two signal acquisition boards. This distance d can be twice the adjacent hole pitch of the coding tape, that is, to prevent two adjacent holes on the continuous coding tape from being blocked. Obviously, this distance d can be a value greater than twice the adjacent hole pitch of the coding tape. Usually, the larger this distance d is, the better the effect of preventing continuous blocked holes is. At the same time, the distance d between adjacent signal acquisition boards can also be different, that is, the distance between signal acquisition board 21 and signal acquisition board 22 is d1, the distance between signal acquisition board 22 and signal acquisition board 23 is d2, and the distance between signal acquisition board 21 and signal acquisition board 23 is d3. These distances d1, d2, and d3 can be the same or unequal values. In practical applications, the distribution of signal acquisition boards 21, 22, and 23 can be flexibly designed according to the specific usage environment, reducing the design limitations. The arrangement of adjacent signal acquisition boards with a certain distance d apart can also be specifically implemented according to the arrangement of adjacent signal acquisition boards with a certain circumferential angle.

[0060] Figure 5 Another slip ring encoder according to an embodiment of the present disclosure is schematically shown.

[0061] In some embodiments of the present disclosure, there are a total of N signal acquisition boards, and adjacent signal acquisition boards are arranged on one side of the coding tape with a central angle interval of 360° / N, where N is an integer greater than or equal to 2. As Figure 5As shown, in one embodiment of the present disclosure, there are a total of 3 signal acquisition boards. The adjacent signal acquisition boards are arranged on one side of the coding tape with a central angle interval of 120°. The largest angle among the adjacent signal acquisition board intervals is 120°. In this embodiment, even when plugging holes occurs at a continuous plurality of positions, as long as the continuous plugging holes are less than 240° (240° = 360° - 120°), the correct output pulse signal can be ensured.

[0062] In some embodiments of the present disclosure, each signal acquisition board includes a second signal sensor. The second signal sensor is configured to generate a plurality of second acquisition signals according to the light emitted from the other side of the coding tape and passing through a plurality of first-type holes when rotating relative to the coding tape; based on the relative position differences between the first signal sensor, the second signal sensor and any one of the plurality of first-type holes, the first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference; a signal processing board, configured to generate a second coding signal based on at least one of the plurality of second acquisition signals; the first coding signal and the second coding signal are used to determine the rotation direction of the slip ring. In this embodiment, two photoelectric sensors can be arranged on the same signal acquisition board, respectively used to generate the first acquisition signal and the second acquisition signal. The distance interval between the two photoelectric sensors can be preset so that the generated first acquisition signal and the second acquisition signal have a preset phase difference. Due to the position differences between any one of the plurality of first-type holes on the encoder and the first signal sensor and the second signal sensor, when any one of the plurality of first-type holes on the encoder rotates to the corresponding positions of the first signal sensor and the second signal sensor at different times, the generated first acquisition signal and the second acquisition signal have a preset phase difference. In this embodiment, the signal processing board is configured to generate a second coding signal based on at least one of the plurality of second acquisition signals. Specifically, it can be: the signal processing board monitors at least one of the second acquisition signals generated by the plurality of signal acquisition boards to generate a second coding signal. When the selected second acquisition signal is lost, other second acquisition signals are selected to generate a second coding signal. Through the first coding signal and the second coding signal with a preset phase difference, the relative rotation direction of the signal acquisition board and the coding tape can be judged, that is, the rotation direction is judged by combining the order of appearance and the phase difference of the first coding signal and the second coding signal.

[0063] In some embodiments of the present disclosure, the preset phase difference between the first acquisition signal and the second acquisition signal generated by each signal acquisition board is between 1 / 4 and 3 / 4 of the signal period. For example, the preset phase of the first acquisition signal and the second acquisition signal is 1 / 4 of the signal period. When the acquisition module rotates along the first direction with the coding tape, the first acquisition signal leads the second acquisition signal by 1 / 4 of the signal period. When the acquisition module rotates along the second direction with the coding tape, the second acquisition signal leads the first acquisition signal by 1 / 4 of the signal period. For example, the preset phase of the first acquisition signal and the second acquisition signal is 3 / 4 of the signal period. When the acquisition module rotates along the first direction with the coding tape, the first acquisition signal leads the second acquisition signal by 3 / 4 of the signal period. When the acquisition module rotates along the second direction with the coding tape, the second acquisition signal leads the first acquisition signal by 3 / 4 of the signal period.

[0064] In some embodiments of the present disclosure, the coding tape has a second type of hole, each signal acquisition board includes a third signal sensor, and each third signal sensor is configured to generate a plurality of third acquisition signals according to the light emitted from the other side of the coding tape and passing through the second type of hole when rotating relative to the coding tape; a signal processing board configured to generate a third coding signal based on at least one of the plurality of third acquisition signals; and the third coding signal is used to determine the number of turns of the slip ring. The second type of hole provided on each signal acquisition board in this embodiment is dedicated to generating the third acquisition signal. Each time the slip ring rotates one turn, each third signal sensor generates a third acquisition signal according to the light emitted from the other side of the coding tape and passing through the second type of hole. Specifically, the second type of hole can be provided on a circumference of the coding tape with a radius different from that of the plurality of first type of holes arranged regularly. The processing board can be configured to select one of the third acquisition signals to generate the third coding signal. Among them, when the selected third acquisition signal is lost, other third acquisition signals are selected to generate the third coding signal.

[0065] Such as Figure 6As shown, in this embodiment, each signal acquisition board includes a first signal sensor, a second signal sensor, and a third signal sensor. When the signal acquisition board rotates relative to the coding tape, the first signal sensor and the second signal sensor on each signal acquisition board respectively and independently generate a first acquisition signal and a second acquisition signal by transmitting the light emitted from the light emitting device on the other side of the coding tape and passing through different multiple first type holes. Since the holes corresponding to the two signal sensors are different, a preset phase difference is generated between the first acquisition signal and the second acquisition signal. The third signal sensor on each signal acquisition board generates a third acquisition signal by transmitting the light emitted from the light emitting device on the other side of the coding tape and passing through the second type holes. Specifically, the slip ring encoder includes multiple signal acquisition boards 21-23. When the signal acquisition board 21 is configured to rotate relative to the coding tape, according to the light emitted from the light emitting device 31 on the other side of the coding tape and passing through multiple first type holes, the three signal sensors of each signal acquisition board respectively generate a first acquisition signal A1, a second acquisition signal B1, and a third acquisition signal Z1; when the signal acquisition board 22 is configured to rotate relative to the coding tape, according to the light emitted from the light emitting device 32 on the other side of the coding tape and passing through the coding tape holes, it generates a first acquisition signal A2, a second acquisition signal B2, and a third acquisition signal Z2; when the signal acquisition board 23 is configured to rotate relative to the coding tape, according to the light emitted from the light emitting device 33 on the other side of the coding tape and passing through the coding tape holes, it generates a first acquisition signal A3, a second acquisition signal B3, and a third acquisition signal Z3; the signal processing board 4, connected to the signal acquisition boards 21-23, is configured to generate a first coding signal A' based on at least one of the multiple first acquisition signals A1-A3; generate a second coding signal B' based on at least one of the multiple second acquisition signals B1-B3; generate a third coding signal Z' based on at least one of the multiple third acquisition signals Z1-Z3. The first coding signal A' is used to determine the rotation speed of the slip ring; there is a phase difference between the first coding signal A' and the second coding signal B' for determining the rotation direction of the slip ring; the third coding signal Z' is used to determine the number of rotations of the slip ring. The first coding signal A', the second coding signal B', and the third coding signal Z' signals processed by the processing module 4 are transmitted to the data acquisition module SPM.

[0066] Based on the above slip ring encoder, the present disclosure also provides a coding method for a slip ring encoder. The following will be combined with Figures 7 - 9 to describe this method in detail.

[0067] Figure 7 Schematically shows a flowchart of a coding method for a slip ring encoder according to an embodiment of the present disclosure.

[0068] As Figure 7As shown, a coding method for a slip ring encoder in this embodiment includes the steps: S1. When the multiple first signal sensors of multiple signal acquisition boards rotate relative to the coding tape, the first signal of each signal acquisition board generates a first acquisition signal based on the light emitted from the other side of the coding tape and passing through multiple first-type holes. S2. Generate a first coding signal based on at least one of the multiple first acquisition signals.

[0069] In step S2, the generated first coding signal can ultimately be used to determine the rotation speed of the slip ring after being processed. The working principle of this embodiment has been introduced in detail in the above other embodiments and will not be elaborated here. In this embodiment, if there are local blockages in the coding tape, different signal acquisition boards will alternately lose position coding information. Due to the existence of multiple signal acquisition boards, the problem that the coding signal fails simultaneously due to continuous blockages of the coding tape can be avoided, the probability of loss of the trigger signal of the coding tape caused by local continuous blockages of the coding tape is reduced, and the maintenance cycle of the coding tape and the signal acquisition board is extended.

[0070] Figure 8 Schematically shows a flowchart of another coding method for a slip ring encoder according to an embodiment of the present disclosure.

[0071] In some embodiments of the present disclosure, the method includes detecting whether the first acquisition signal is lost, and indicating the abnormal position of the coding tape based on the position where the first acquisition signal is lost.

[0072] As Figure 8 shown, in this embodiment, after generating the first acquisition signal based on the light emitted from the other side of the coding tape and passing through multiple first-type holes when the multiple first signal sensors of multiple signal acquisition boards rotate relative to the coding tape in operation S1, the steps include: detecting whether the first acquisition signal is lost. If there is a lost first acquisition signal, the position of the lost first acquisition signal is the abnormal position of the coding tape, and the abnormal position of the coding tape is indicated. Then continue with step S2 where the signal processing board generates a first coding signal based on at least one of the multiple first acquisition signals. In specific implementation, if there are local blockages in the coding tape, when different signal acquisition boards rotate to the blocked hole position, they will alternately lose position coding information; if it is a fault of the signal acquisition board, this signal acquisition board will always be unable to give a pulse signal, and the type of fault can be discriminated based on this for alarm.

[0073] In some embodiments of the present disclosure, generating a first coding signal based on at least one of the multiple first acquisition signals includes: selecting one of the first acquisition signals to generate the first coding signal. Among them, when the selected first acquisition signal is lost, select other first acquisition signals to generate the first coding signal. For the related principle, refer to Figure 4 and related embodiments.

[0074] In some embodiments of the present disclosure, the method includes: when the plurality of second signal sensors of the plurality of signal acquisition boards rotate relative to the coding tape, generating a plurality of second acquisition signals according to the light emitted from the other side of the coding tape and passing through the plurality of first type of holes;

[0075] The first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference; generating a second coding signal based on at least one of the plurality of second acquisition signals; determining the rotation direction of the slip ring based on the first coding signal and the second coding signal. Wherein, each signal acquisition board includes a second signal sensor, and based on the relative position difference between the first signal sensor, the second signal sensor and any one of the plurality of first type of holes, the first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference.

[0076] Figure 9 Schematically shows a flowchart of another slip ring encoder coding method according to an embodiment of the present disclosure.

[0077] In some embodiments of the present disclosure, the method includes: when the plurality of first signal sensors and the plurality of third signal sensors of the plurality of signal acquisition boards rotate relative to the coding tape, the plurality of first signal sensors generating a plurality of first acquisition signals according to the light emitted from the other side of the coding tape and passing through the plurality of first type of holes; and / or the plurality of third signal sensors generating a plurality of third acquisition signals according to the light emitted from the other side of the coding tape and passing through the second type of holes; generating a third coding signal based on at least one of the plurality of third acquisition signals; determining the number of rotation turns of the slip ring based on the third coding signal. Wherein, the coding tape has one second type of hole, and each signal acquisition board includes a third signal sensor.

[0078] In some embodiments of the present disclosure, determining the number of turns of the slip ring based on the third encoded signal includes: generating a first encoded signal based on at least one of a plurality of first acquisition signals, accumulating the first encoded signal, and incrementing the number of turns of the slip ring value when the accumulated count value of the first encoded signal reaches a preset value and the third encoded signal is present. For example, in this embodiment, one turn of the slip ring can generate a preset number of first encoded signals. When the third encoded signal cannot be generated normally due to various reasons, the accumulated value of the first encoded signal can be used to reach the preset value to determine that the number of turns of the slip ring value is incremented by one. If the third encoded signal is normal, the accumulated value of the first encoded signal can be used for mutual verification. For example, when a third encoded signal is generated, the accumulated value of the first encoded signal should also reach the preset value. At this time, the accumulated value of the first encoded signal is cleared and the accumulation starts again. At the same time, there may be a problem of signal loss when the first encoded signal and the third encoded signal are sent to the data acquisition module. By designing the mutual verification between the two, this embodiment can further improve the fault detection ability of the coding tape and facilitate timely detection of whether there is a fault condition. In some embodiments of the present disclosure, the second encoded signal can also be accumulated and mutually verified with the third encoded signal, and the essence is the same, so it will not be elaborated here.

[0079] As Figure 9 shown, in some embodiments of the present disclosure, the first encoded signal is used for cumulative counting. When the accumulated count value of the first encoded signal reaches a preset value and the third encoded signal is present, the number of turns of the slip ring value is incremented by one. In this embodiment, in step S1 when the coding tape and the signal acquisition board rotate relative to each other, each signal acquisition board generates a first acquisition signal and / or a third acquisition signal according to the light emitted from the other side of the coding tape and passing through a plurality of first-type holes. In step S2, the signal processing board generates a first encoded signal based on at least one of the plurality of first acquisition signals, and generates a third encoded signal based on at least one of the plurality of third acquisition signals. After step S2, it includes accumulating the first encoded signal, and determining whether the accumulated value of the first encoded signal reaches the preset value and whether the third encoded signal is generated. When the accumulated value of the first encoded signal reaches the preset value or the third encoded signal is generated, the accumulated count value of the first encoded signal is cleared and the number of turns of the slip ring value is incremented by 1. When the accumulated value of the first encoded signal does not reach the preset value, wait for the next acquisition signal. For example, in this embodiment, there are 1440 first-type holes in the coding tape, and it is determined whether the accumulated value of the first encoded signal reaches 1440. When the first encoded signal is fully accumulated to 1440, the third encoded signal is also generated at this time, and the number of turns of the slip ring value is incremented by 1. When the first encoded signal is fully accumulated to 1440 and the third encoded signal is not generated, there may be an abnormality in the generation process of the third encoded signal, and a prompt for troubleshooting can be given.

[0080] Based on the above slip ring encoder and encoding method, the present disclosure also provides a CT device. The following will be combined with Figures 10 - 11Describe the method in detail.

[0081] As Figures 10 - 11 shown, Figure 11 is a partial enlargement of part a in Figure 10 A CT device according to this embodiment includes the encoder of the above embodiment. A coding tape 1 and a slip ring 5 are installed on the CT device body 6, and signal acquisition boards 21-23 are distributed on the slip ring 5. In this embodiment, the coding tape 1 remains stationary when the slip ring 5 rotates. The signal acquisition boards 21-23 are arranged on one side of the coding tape at a certain distance from each other. Each signal acquisition board is configured to generate a first acquisition signal according to the light emitted from the other side of the coding tape and passing through a plurality of first-type holes when rotating relative to the coding tape. A plurality of long holes can be provided on the coding tape, and each long hole can be installed with 1 pressing piece for fixing the coding tape to the CT device body. The pressing plate has a bend to press the coding tape to prevent the coding tape from deforming.

[0082] The above detailed description has set forth numerous embodiments of the slip ring encoder and its encoding method by using schematic diagrams, flowcharts, and / or examples. In cases where such a schematic diagram, flowchart, and / or example includes one or more functions and / or operations, those skilled in the art should understand that each function and / or operation in such a schematic diagram, flowchart, or example can be implemented individually and / or jointly by various structures, hardware, software, firmware, or substantially any combination thereof. In one embodiment, several portions of the subject matter described in embodiments of the present invention can be implemented by application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, those skilled in the art should recognize that some aspects of the embodiments disclosed herein can be equivalently implemented, in whole or in part, in integrated circuits, implemented as one or more computer programs running on one or more computers (e.g., implemented as one or more programs running on one or more computer systems), implemented as one or more programs running on one or more processors (e.g., implemented as one or more programs running on one or more microprocessors), implemented as firmware, or substantially implemented as any combination of the above, and those skilled in the art will have the ability to design circuits and / or write software and / or firmware code based on this disclosure. In addition, those skilled in the art will recognize that the mechanisms of the subject matter described in this disclosure can be distributed as a variety of program products, and the exemplary embodiments of the subject matter described in this disclosure apply regardless of the specific type of signal-bearing medium actually used to perform the distribution. Examples of signal-bearing media include, but are not limited to: recordable media such as floppy disks, hard disk drives, compact discs (CDs), digital versatile discs (DVDs), digital magnetic tapes, computer memories, etc.; and transmission media such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0083] The embodiments of the present disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims

1. A slip ring encoder, characterized in that: Comprising: A coding band having a plurality of first - type holes arranged regularly; A plurality of mutually independent signal acquisition boards arranged on one side of the coding band. Each signal acquisition board includes a first signal sensor, and the first signal sensor is configured to generate a first acquisition signal according to the light emitted from the other side of the coding band and passing through the plurality of first - type holes when rotating relative to the coding band; A signal processing board electrically connected to the plurality of signal acquisition boards and configured to generate a first coding signal based on at least one of the plurality of first acquisition signals.

2. The slip ring encoder according to claim 1, wherein, The plurality of signal acquisition boards are arranged on one side of the coding band based on generating a plurality of first acquisition signals having substantially the same phase.

3. The slip ring encoder according to claim 1, wherein, The plurality of signal acquisition boards are separately arranged from the signal processing board.

4. The slip ring encoder according to claim 1, characterized in that, The generating the first coding signal based on at least one of the plurality of first acquisition signals includes: The signal processing board is configured to select one of the first acquisition signals to generate the first coding signal; Wherein, when the selected first acquisition signal is lost, select other first acquisition signals to generate the first coding signal.

5. The slip ring encoder according to claim 1, characterized in that, The adjacent signal acquisition boards are arranged on one side of the coding band with a central angle interval of more than 1°.

6. The slip ring encoder according to claim 1, characterized in that Each signal acquisition board includes a second signal sensor, and the second signal sensor is configured to generate a second acquisition signal according to the light emitted from the other side of the coding band and passing through the plurality of first - type holes when rotating relative to the coding band; Based on the relative position difference between the first signal sensor, the second signal sensor and any one of the plurality of first - type holes, the first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference; The signal processing board is configured to generate a second coding signal based on at least one of the plurality of second acquisition signals; The first coding signal and the second coding signal are used to determine the rotation direction of the slip ring.

7. The slip ring encoder according to claim 6, characterized in that: The preset phase difference between the first acquisition signal and the second acquisition signal generated by each signal acquisition board is between 1 / 4 - 3 / 4 signal periods.

8. The slip ring encoder according to claim 1, characterized in that: On the circumference of the coding band different from the radius of the first - type holes, there are second - type holes; each signal acquisition board includes a third signal sensor, and the third signal sensor is configured to generate a third acquisition signal according to the light emitted from the other side of the coding band and passing through the second - type holes when rotating relative to the coding band; The signal processing board is configured to generate a third coding signal based on at least one of the plurality of third acquisition signals; the third coding signal is used to determine the number of rotation turns of the slip ring.

9. A method for encoding a slip ring encoder, applied to the slip ring encoder according to claims 1 to 8, characterized in that: The method includes: When the plurality of first signal sensors of the plurality of signal acquisition boards rotate relative to the coding band, generating a plurality of first acquisition signals based on the light emitted from the other side of the coding band and passing through the plurality of first - type holes; Generating a first coding signal based on at least one of the plurality of first acquisition signals.

10. The encoding method according to claim 9, characterized in that Including, detecting whether the first acquisition signal is lost; based on the lost position of the first acquisition signal, indicating the abnormal position of the coding band.

11. The encoding method according to claim 9, characterized in that, Generating a first encoded signal based on at least one of the multiple first acquisition signals includes: Selecting one of the first acquisition signals to generate the first encoded signal; Wherein, when the selected first acquisition signal is lost, select other first acquisition signals to generate the first encoded signal.

12. The encoding method according to claim 9, characterized in that Includes: When the multiple second signal sensors of the multiple signal acquisition boards rotate relative to the encoding tape, generating multiple second acquisition signals according to the light emitted from the other side of the encoding tape and passing through the multiple first type of holes; Generating a second encoded signal based on at least one of the multiple second acquisition signals; Determining the rotation direction of the slip ring based on the first encoded signal and the second encoded signal; Wherein each of the signal acquisition boards includes a second signal sensor, and based on the relative position differences between the first signal sensor, the second signal sensor and any one of the multiple first type of holes, the first acquisition signal and the second acquisition signal generated by each signal acquisition board have a preset phase difference.

13. The encoding method according to claim 9, characterized in that Includes: When the multiple third signal sensors of the multiple signal acquisition boards rotate relative to the encoding tape, generating multiple third acquisition signals according to the light emitted from the other side of the encoding tape and passing through the second type of holes; Generating a third encoded signal based on at least one of the multiple third acquisition signals; determining the number of rotation turns of the slip ring based on the third encoded signal; Wherein the second type of holes are arranged on a circumference of the encoding tape with a different radius from the first type of holes, and each of the signal acquisition boards includes a third signal sensor.

14. The encoding method according to claim 13, wherein: The determining the number of rotation turns of the slip ring based on the third encoded signal includes: Accumulating the first encoded signal, and when the accumulated count value based on the first encoded signal reaches a preset value and the third encoded signal, incrementing the number of rotation turns value of the slip ring by one.

15. A CT device, characterized in that: Comprises the slip ring encoder as claimed in claims 1-8.

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