High density rotary joint for non-contact data transfer

Abstract

A rotary capacitive data link system includes a first body rotatable relative to a second body. The first body has one or more loop signal transmission lines having a plurality of transmission line segments. The second body has a plurality of receiving coupler groups arranged annularly, the receiving coupler groups having a plurality of receiving couplers. Each of the groups of receive couplers matches one of the ring signal transmission lines such that there are a plurality of capacitive coupling paths between the transmission line segment and the receive couplers of the matching group of receive couplers depending on the relative rotational position or angle between the first body and the second body. A received signal processor is provided to generate a detailed error or state matrix of transmission errors.

Description

Technical Field

[0001] The present invention relates to a rotary joint for contactless data transmission based on capacitive coupling technology. In order to obtain very high data rates with very low data loss, multiple capacitive links are combined with a multiplexing scheme related to the rotation angle. This allows higher data transmission bandwidth while maintaining the existing size of the slip ring (slipring, collector ring) system. The increased complexity requires intelligent system diagnosis. Such a rotary joint can be used in a CT scanner. Background Art

[0002] In US 7,466,794 a multi-channel data transmission system for computed tomography is disclosed, which was further improved by EP 2932901. To improve transmission reliability, existing diagnostics as described in US 8,013,468 B2 and US7240251 B2 help to find single errors in single transmission links, but are of limited benefit in these complex systems with potentially 36 or more data transmitter and receiver components generating 16 parallel multiplexed data transmission links using fast and cyclically switched communication devices which, when misaligned or defective, may cause not only static errors but also dynamic errors.

[0003] US2008 / 0069146 A1 discloses a multi-channel data transmission system for computed tomography. EP2 775 630 A1 discloses a high-speed network contactless rotary joint. US2005 / 0005206A1 discloses a method and system for data transmission in a CT device with integrated error monitoring and diagnostic functions. EP 2 932 901 A1 discloses a rotary joint for multi-channel high-speed data transmission. Summary of the invention

[0004] The problem to be solved by the present invention is to provide an improved capacitive data link system having very high data rates, very low data losses and high reliability, by allowing simple diagnostics to accurately show misalignment of data transmission components and facilitating a quick and targeted discovery of defective components, avoiding trial and error strategies when servicing such equipment. Furthermore, the data link diagnostic features should not increase the space requirements, so that the system can be adapted to the space available in a CT scanner. Furthermore, the system should facilitate commissioning and servicing of such a multiplexed capacitive data transmission system.

[0005] The solution to the problem is described in the independent claim. The dependent claims relate to further developments of the invention.

[0006] A rotary capacitive data link system includes a first body and a second body, wherein the first body is rotatable relative to the second body about a rotation axis. This includes the first body being static and the second body being rotatable or otherwise. In addition, the two bodies can rotate at different speeds.

[0007] The first body includes at least one annular signal transmission line, whereby each annular transmission line includes at least two transmission line segments, each segment being connected to a transmitter. The segment may be separated by at least one small mechanical gap. Such a gap may be a gap in a substrate that holds a separate transmission line conductor, or a gap between separate transmission line conductors. There may be more transmission lines and / or transmission line segments, which may contribute to increasing data rates and improving transmission quality. The transmission line segments may all have the same length. The number of transmission line segments may be the same for all annular transmission lines, but may be different between transmission lines in different settings. In addition, a multiplexed capacitive data transmission system and a standard (non-multiplexed in space) capacitive data transmission system may be combined, for example, a standard system for uplink (stator to rotor or second to first body) has a different total data rate compared to a downlink multiplexed capacitive data transmission system (rotor to stator or first to second body).

[0008] The second body includes at least two annularly arranged receiver coupler sets, wherein each annularly arranged receiver coupler set includes at least two receiver couplers arranged circumferentially around the rotation axis.

[0009] Each of the groups of receiving couplers matches one and another receiving coupler in the ring signal transmission line, using this configuration, it is ensured that there is always at least one receiver picking up the signal of one transmission line section so that no data is lost. Each receiving coupler is connected to one receiver.

[0010] Typically, for high data rate applications, single or multiple ring transmission lines are arranged in the form of transmission line segments covering only a small portion (e.g., a quarter) of the circumference, with each segment transmitting a data stream. The signal is picked up by one or more receiving couplers (each receiving coupler is connected to a receiver) (e.g., 5), thereby ensuring that each receiver has no data loss or distortion during the relative movement of its receiving coupler when it moves by rotating between two transmission line segments. When the receiver rotates between one segment and the next, there is a gap in the data transmission caused by signal distortion and signal loss, which is caused by the small mechanical gap and signal changes between the two transmission line segments connected to different transmitters. In the following, the stage when the data received by the receiver is corrupted or the frame is not assessable is called the frame gap. This frame gap has a certain length in time, depending on the mechanical alignment of the receiving coupler with the transmission line segment involved, the mechanical gap between the segments, the rotation speed, the size of the receiving antenna, the characteristics of the PLL (phase-locked loop) of the receiver, the data rate, the frame size plus the digital synchronization time required for the descrambling part of the detection and synchronization frame. In the case of a defective receiver, the frame gap may be larger than usual. The multiplexer can sort out damaged and duplicate data frames. It can also sort the transmission frames according to the sender address in the frame header.

[0011] In a different setup, the number of transmission line sections may be one higher than the number of receivers, allowing the same type of data processing and diagnostics, with the only disadvantage being that the data sent by the one additional transmitter must be generated with a complex algorithm so that there is no data loss during the rotation.

[0012] In addition, the transmitting side (transmit signal processor) can encode and repack the data stream, inserting frames including: addresses to allow reordering and send channel-related diagnostics; and checksums to check data packets for transmission errors and other distortions. In addition, the data can be encoded, inserting additional information for subsequent forward error correction (FEC). In addition, the data can be scrambled using a pseudo-random bit sequence (PRBS) code to reduce unwanted radiation to values ​​well below EMC limits during transmission of the data. In the following, a frame including a header and data for sorting or for diagnostics or data quality is referred to as an SR-frame, but it can be any type of frame, an additionally inserted frame, a user-defined protocol frame, or a standardized protocol frame, such as an Ethernet or IO-Link frame, if all the necessary information is included as described above.

[0013] There is a transmit signal processor at the first body and a receive signal processor at the second body. Each of the transmission line segments is connected to the transmit signal processor at the first body, and each of the receive couplers is connected to the receive signal processor at the second body. This allows downlink data communication from the transmit signal processor at the first body to the receive signal processor at the second body via the transmission line segment and the receive coupler. The transmit signal processor may include multiple transmitters connected to the transmission line segment. A separate transmitter may be connected to each of the transmission line segments. The receive signal processor may include multiple receivers connected to the receive coupler. A separate receiver may be connected to each of the receive couplers. The transmit signal processor and / or the receive signal processor may include an FPGA and / or a microcontroller, or may be part of an FPGA and / or a microcontroller.

[0014] According to the relative rotation position or angle between the first body and the second body, there are multiple capacitive coupling paths between the transmission line segment of each annular signal transmission line and the matching receiving coupler. A high-speed data stream of a user channel can be converted into multiple low-speed data streams by a transmitting signal processor, and the multiple low-speed data streams are transmitted through multiple capacitive coupling paths, and at least one high-speed data stream of the user channel is assembled back in the receiving signal processor. Alternatively, the existing parallel data streams are transmitted in parallel links, or several data streams, Ethernet frames or other protocols-such as slower control buses and other signals (for example, IO links, CAN buses, encoder data, other HW trigger signals, etc.)-can also be multiplexed together, thereby contributing to the data stream. If data and signals are multiplexed on the rotor of the system, they are demultiplexed (downlink) on the stator, and vice versa in the case of uplink configuration. An uplink can be provided, and an uplink receiver at the first body matched with the uplink transmitter of the second body can be included. This allows data communication in the opposite direction from the second body to the first body. The uplink transmitter may include at least one signal ring transmission line having at least one signal transmission line segment. The uplink receiver may include at least one receiving coupler. The uplink may be based on any suitable transmission technology, including slip rings, capacitive data links, inductive data links, optical rotary joints. The uplink may also include one or more of several parallel data links.

[0015] The uplink and downlink may have different aggregate data transmission capacities. Typically, the uplink is used only for signaling and communication protocols, so that it has a lower data rate than the downlink.

[0016] The receive signal processor is also configured to provide at least one detailed error or state matrix, which can also be used for field service support. Such an error or state matrix can be provided in real time. Generally, embodiments relate to a matrix that can show errors or states of a data link system. Generally, an error can be considered as a specific state. The state matrix can include:

[0017] Status information, such as a value or count,

[0018] Error information about the error, e.g., value or count,

[0019] Information about error-free transmission, e.g. values ​​or counts,

[0020] Or all of them.

[0021] The terms "state matrix," "error matrix," and "error or state matrix" are used herein for such matrices.

[0022] The error or state matrix includes at least one data field for each available or matching combination of a transmission line segment and a receiving coupler. In one embodiment of a two-dimensional matrix, the error or state matrix has a row for each transmission line segment and a column for each receiving coupler. The matrix can have more dimensions, for example, it can cover data rate, data format, such as the operating conditions of temperature or voltage. In the above-mentioned two-dimensional matrix, only the data field of the effective or available / matching combination of the transmission line segment and the receiving coupler can be occupied. All other data fields can be marked as invalid. For the entire rotating capacitor data link system, a single error or state matrix can be present, or a separate matrix can be present for each combination of a transmission line segment and a receiving coupler. The error or state matrix for uplink and downlink can be separated, or combined in a multidimensional matrix. The setting and content of the error or state matrix can be read, evaluated, stored and displayed by a controller, for example, by a service PC by reading and modifying the registers of sending, receiving and transceiver signal processors. The connection between the controller and the processor can be realized via a data link, which is a part of a controlled data link system. For redundancy in the event of a fault, this connection can be signaled via different paths.

[0023] An embodiment of such a matrix is ​​given below, in which the first body comprises two annular signal transmission lines, each comprising 3 segments (each segment being driven by a transmitter connected to a data link), and the second body comprises two receiving coupler groups, each group comprising two couplers.

[0024] Since the position of the components transmitter and connected transmission segments and receiving coupler and connected receiver are defined by the wiring, incorrect wiring can be detected, for example, if the line and coupler do not fit together. This is shown as an error, but the diagnostic system may also ignore it if the error does not lead to a functional error (for example, if the frame is correctly classified).

[0025]

[0026] Line 1 matches group 1, and line 2 matches group 2. Only matching pairs can communicate with each other. Therefore, only the combination of line 1 and group 1 and line 2 and group 2 can contain valid error counter values. The data fields of all other combinations are marked as invalid. Data fields marked with E(xx, yy) can contain certain error values. For example, E(13, 12) can contain an error counter for the error of the transmission of a signal from line 1, segment 3 to coupler 2 of group 1. Here, the first digit x of E(xx, yy) is the line number and the second digit x is the segment. The first digit y is the group, and the second digit y is the coupler number.

[0027] The error or status matrix may contain flags or counters for errors, such as code errors (e.g., 8b10b encoding not detected), frame errors (such as, for example, CRC errors), signal loss, or it may indicate the status or availability of individual combinations of transmission line segments and receive couplers. If the CRC value contained within a frame does not agree with the calculated CRC value for the frame, a CRC error is detected and the CRC counter may be incremented.

[0028] The error or state matrix may also be populated with state information showing state information, or calculated fitness information showing which signals are valid or connected, calculated from the error counter values ​​implemented as a state matrix. For ease of description, only the error or state matrix is ​​described.

[0029] A detected error will increment counters assigned to the transmit side (transmitter connected to the transmission segment) and the receive side of the channel, allowing later correlation of the error, e.g. an error count is distributed over all transmit channels but only one receive channel (receiver and connected receive coupler) shows that it is relevant to the receive channel.

[0030] Below is the error or state matrix for a perfectly working data link system, where the data field contains, for example, the code errors per second:

[0031]

[0032]

[0033] Here, all valid combinations of transmission line segments and receive couplers have zero encoding error every second.

[0034] For example, if segment 2 of line 1 is slightly misaligned, the error rate may increase for all combinations with that segment:

[0035]

[0036]

[0037] For example, if coupler 1 of set 2 is slightly misaligned, the error rate may increase for all combinations with that coupler, resulting in higher error counts per measurement time:

[0038]

[0039]

[0040] The error matrix clearly shows the relationship between errors and segments / couplers so that it can be used for automatic or manual error analysis.

[0041] Based on the contents of the error or state matrix, the multiplexing of channels can be changed to avoid slow or defective combinations of transmission line segments and receiving couplers.

[0042] In one embodiment, a controller is provided that is configured to evaluate an error or state matrix and provide an error or state indication and / or provide reconfiguration of a transmit signal processor and / or a receive signal processor based on a data field value.

[0043] Instead of the error count per time interval, the error rate can also be displayed, for example, 1.15 10 -3 .

[0044] A method for status assessment of a rotating capacitive data link system, the system comprising at least one transmission line, the at least one transmission line having at least two transmission line segments connected to at least two receiving couplers, the method comprising the steps of: generating an error or status matrix, the matrix comprising at least one data field for each available combination of transmission line segments and receiving couplers, wherein at least one data field (910) is configured to contain at least one of an error and / or status indication value. The method may be combined with any of the features disclosed herein. The method may also include steps for performing any of the features disclosed herein. The method may be applied to a system as disclosed herein.

[0045] The receive signal processor may be configured to perform real-time receiver-based diagnostics, which may be used for additional general troubleshooting purposes. The following checks may result in receiver status signals as specified below:

[0046] a) Validity of coded data: When the received and coded data (e.g. 8b10b) is considered good, a signal indicating the validity of the coded data can be given. Such a signal can be given after a minimum of 8μs of reception without any code errors. At this stage, only blocks of the line code used are analyzed.

[0047] b) Validity of the frame: When a valid frame is received within a minimum time interval (e.g., at least 100 milliseconds), a signal indicating the validity of the frame can be sent. At this stage, only the frame is analyzed. A frame is a simple container for a single network packet and can include multiple data blocks.

[0048] The results may be stored as counters or flags in an error or state matrix.If both signals are valid during slip ring standstill and / or rotation, then all receivers are likely operating correctly.

[0049] If during the rotation one or both signals are invalid for at least one receiver, the receiver is defective or not supplied with power, or the receiving coupler connected to the receiver is incorrectly adjusted. For this case, the receiver is connected to a data switch via an optical fiber, the fault condition may also be a broken fiber or a fragment at one end of the fiber causing increased bit errors.

[0050] If one or both signals are invalid for exactly one receiver, this may be the result of stagnation of a receive coupler located at the transmission line gap (mechanical gap) between two different transmission lines.

[0051] This diagnostic may be implemented for each receiver.

[0052] The receive signal processor can be configured to perform real-time user channel based diagnostics. The following checks result in a link status signal:

[0053] a) Validity of transmission frame rate: If the number of frames received per time unit is within the valid interval, a signal indicating the valid transmission frame rate may be issued. The measured frame rate may be low-pass filtered before being compared with the upper and / or lower limit values.

[0054] b) Transmission loss rate: Based on the counted lost frames during a specified time interval, a signal indicating the rate of lost frames can be issued. The measured frame rate can be low-pass filtered before comparing it to the limit value. If a transmission loss is detected, for example due to a defective transmitter or a transmitter without power supply, a signal indicating the transmission loss can be issued. For this case, the transmitter is connected to the data source via an optical fiber, and the fault condition can also be a broken fiber or a fragment at one end of the fiber causing increased bit errors.

[0055] If the frame rate is in a valid range and the transmission loss rate is below a predetermined limit, a good user channel signal can be sent.

[0056] This diagnostic may be performed for each user channel.

[0057] The receive signal processor may be configured to perform interframe gap analysis.During operation of the link, a counter matrix is ​​generated to count frame losses and / or measure interframe gaps, for example, for each receive coupler and / or each group of receive couplers.

[0058] Snapshots of the frame gap counter matrix can be stored periodically in a system server log file or database. This may be useful if the receive signal processor does not contain non-volatile memory. Therefore, snapshots of the frame gap counter may need to be stored outside the receive signal processor, for example, in a log file or database on a system server. It may be recommended to store a new snapshot including a timestamp every hour, but only in the case of an error (if there is a difference in the counter value). These stored snapshots can be post-processed for analysis, including error location - including RX (receive) / TX (send) error separation, evaluation of error severity (number of transmission gaps) and evaluation of trends and degradation (over time).

[0059] Gaps in the received frame counter values ​​(which are part of the frame header and, if not already included, are generated and inserted by the transmit signal processor) are clear evidence for lost frames (SR-frames). When there are gaps in the continuous frame stream, the corresponding frame loss counters and frame gap counters will be incremented accordingly. Frame losses and / or frame gaps are counted in counters associated with the transmitter and transmission line segment addresses or numbers and with the receiver and receive coupler addresses or numbers so that it is possible to distinguish between error conditions caused by the transmitting side (e.g., transmitter or associated transmission line or transmission line segment) or by the receiving side (e.g., receive coupler, associated receiver). By sorting / displaying these frame loss and / or frame gap counters in a matrix, the cause of the error can be easily evaluated for debugging.

[0060] If a frame loss event occurs within a channel switch, the loss of a frame cannot always be clearly assigned to one receiving channel. This is called an ambiguous loss event. In the case of an ambiguous loss event, the counter values ​​of both receiver channels involved (the fade-out channel and the fade-in channel) will be incremented. In the case of an ambiguous event, the loss counter will be increased for each frame lost, but the frame loss counters of both receivers are incremented. The frame loss counter and the gap counter of the transmitter are incremented.

[0061] The interframe gap has a width / length determined by at least one of the receive coupler length, the gap between adjacent signal transmission lines, the PLL stabilization time, the rotation speed, and the protocol frame length. This length is constant with only slight jitter. The length of the gap may deviate only when there is distortion caused by, for example, a faulty PLL in the receiver, a misaligned receive antenna, or a transmit antenna. The gap of the received frame sequence can be monitored in its start and end position and by its time or by encoder position and a signal to the service engineer indicating the drift or deviation of the position and width.

[0062] The frame gap can be evaluated with respect to the rotation speed. It should decrease with increasing speed up to a certain limit, where the gap value is determined by the PLL settling time and the frame length.

[0063] The frame gaps can be displayed and evaluated with respect to the rotation angle - the gap positions in an error-free system are distributed in direct relation to their mechanical positions. This results in an equally spaced distribution, but this may also be different if the angles are not the same but some of the receivers differ from the ideal position (for example, due to mechanical reasons arising from the structure of the system). Each of the receivers can have a PLL (Phase Locked Loop) that synchronizes the digital receiver with the received serial protocol. The clock can be recovered by the PLL evaluating the serial information transitions, which have a specific density guaranteed by the encoding, which can be 8b10b or 64b66b.

[0064] The error or state matrix may contain error values ​​and / or interframe gap values ​​and / or loss counters. It may also contain state information generated by these values. The values ​​may be incremented until deleted, or may be counted over defined time intervals to generate error rates, or to show different effects (e.g., over time or at different speeds).

[0065] The error or state matrix can be displayed as (real-time = regularly updated) receiver-oriented diagnostics for general troubleshooting purposes, or as real-time user channel-oriented diagnostics for general troubleshooting purposes, a user channel is usually represented by a transmitter or transmission line segment.

[0066] In one embodiment, the transmission line segment completely surrounds the first body, which may have a cylindrical shape. The number of transmission line segments may be different from the number of matched receiving couplers. This is particularly useful if the transmission line segments have the same length and the matched receiving couplers are equally spaced. As with the same number of segments and couplers, if all couplers are located at the mechanical gap between the transmission line segments, there is no signal coupling. With respect to different numbers (if the number is not too high), only one coupler may be at the mechanical gap at a time. The other couplers may receive undistorted signals. The same result may be achieved by having transmission line segments of different lengths and / or by unequal spacing of receiving couplers.

[0067] Embodiments may include: a disk-shaped arrangement in which the transmission line segments are arranged and / or spaced axially, or a cylindrical or drum-shaped arrangement in which the transmission line segments are arranged and / or spaced radially, or a combination thereof.

[0068] An example protocol, referred to herein as the SR protocol, is described below:

[0069] Protocol Structure

[0070] SR-Protocol: byte Character Start of Frame (SOF) 4 0，5 Scrambler Seed (SCS) 4 0，5 Frame Counter 4 0，5 Source Address 2 0，25 Reserved 2 0，25 Payload TDATA 1024 128 PayloadTUSER 16 2 Frame validity information 16 2 CRC 8 1 Internal grouping gap 8 1 Overview: SR-protocol overhead 16 2 SR-frame overhead 32 4 SR-Frame Payload 1040 130 SR-frame length 1072 134 Total packet length 1088 136 Total expenses 48 6 Protocol efficiency (%) 95,58 8b10b efficiency (%) 80 Overall efficiency (%) 76,47

[0071] The SR protocol generates a continuous stream of packets of constant size, called SR-frames.

[0072] Scrambling

[0073] SR-frames (as an embodiment of the frame protocol definition) use data scrambling (polynomial: x31+x28+1) to reduce electromagnetic interference. The entire SR-frame as well as the IPG (inter-packet gap) are scrambled. The only unscrambled parts are the SOF and SCS fields of the SR protocol. This results in a flat spectrum with negligible impact of the unscrambled parts of the protocol.

[0074] A high-level diagnosis may include the following three features:

[0075] SR-frame k SR-frame k+1

[0076]

[0077]

[0078] FEC secure data transmission

[0079] Data transmission can be protected by FEC (Forward Error Correction). This feature has not yet been implemented into the GigaCAP HD IP core. However, other GigaCAP products are equipped with such FEC and are in production and in the field since 2016.

[0080] FEC will operate on SR protocol frames. Each frame will contain its own FEC information. One frame will be transmitted on one GigaCAP channel. No stretching of frames over several GigaCAP channels will be performed. GigaCap and GigaCapHD refer to capacitive transmission line systems. GigaCap is a non-multiplexed transmission line system. GigaCap HD is a rotationally dependent multiplexed transmission line system.

[0081] Here are some numbers on how FEC might perform:

[0082]

[0083] BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Hereinafter, with regard to examples of embodiments with reference to the accompanying drawings, the present invention will be described by way of example without limiting the general inventive concept.

[0085] FIG. 1 shows the basic concept of an embodiment.

[0086] Figure 2 A rotation dependent multiplexer is shown compared to a standard system.

[0087] Figure 3 A system with 4 rings and 4 sections per ring is shown.

[0088] FIG4 shows a block diagram of one embodiment.

[0089] Figure 5 High-level diagnostic measures and benefits are shown.

[0090] Figure 6 The frame numbers of frames transmitted from two transmitters to one receiver are shown.

[0091] Figure 7 The frame numbers of the frames transmitted from the two transmitters to the two receivers are shown.

[0092] Figure 8 One implementation of a frame gap matrix is ​​shown.

[0093] Fig. 9 A block diagram of another embodiment is shown.

[0094] Figure 1 consists of two parts: Figure 1a and Figure 1b. It shows the basic concept of an embodiment of a rotary capacitive data link system (100) using a position, and therefore the top part of the figure shows a multiplexing scheme dependent on the rotation angle. Multiple (for example, four) such data links can be connected in parallel to improve throughput and reliability. Only one such link is shown here, which connects the first body 110 "rotor" to the second body 120 "stator", having a transmission line for transmitting signals of two channels "a" and "b". Each channel can have at least one optoelectronic converter "OE" for converting optical signals into electrical signals and vice versa. At least one optoelectronic converter "OE" drives a transmitter "Tx" 410, 411 for each channel, further driving at least one transmission line segment in a ring shape. There may be a greater number of channels, optoelectronic converters, transmitters and transmission line segments.

[0095] The signal is received by a receive coupler, which is shown as a short arc shaped segment. There may be one more receive coupler 311, 312, 313 than transmission line segments, in this case 3. The receive couplers are connected to receivers "Rx" 510, 511, 512 and also to at least one optoelectronic converter "OE". These are further connected to a switching device, which reduces (demultiplexes) the number of lines, here from 3 to two output lines "a" and "b". As stated, multiple transmission lines can be stacked, only one is shown in this case.

[0096] Below are diagrams showing different reception phases when a receiver mounted to the second body (stator) receives a signal transmitted by a rotating transmitter.

[0097] (1) When the receiver leaves one transmission line segment to transfer to the next transmission line segment, (Case 1) the data frame may be cut off (b4), and damaged data may be received for a period of time (X) before the signal is received again (a5), but the complete frame may not be received (a5), or the frame header may not be detected on the first frame.

[0098] (2) The receive signal processor needs to evaluate the received frame by reading the frame header to allocate the stream. In addition, the lost or defective data can be counted.

[0099] (3) In addition, the receive signal processor may find duplicate received frames and delete one so as not to increase the overall data rate through redundant information.

[0100] Figure 1a An enlarged left side of FIG. 1 is shown. Figure 1b An enlarged view of the right side of FIG. 1 is shown.

[0101] Figure 2A rotation dependent multiplexer is shown compared to a standard system. In a standard capacitive link system, a transmission line has only one segment, and the transmission line segment is connected to one transmitter or multiple segments are connected to the same transmitter. A receiving coupler connected to a receiver receives the signal transmitted during the rotation, and the transmission line covers nearly 360 degrees. Multiple (N) such data links can be connected in parallel to increase throughput.

[0102] In one embodiment according to the invention, each transmission line comprises a plurality of segments, each segment being connected to a transmitter. At least one more (N+1) receiving couplers are implemented - each having a receiver connected to a receiver, and then the transmitter (N) and the transmission line segment. The receiving signal processor removes damaged and double received frames.

[0103] If dimensioned correctly, a rotationally dependent multiplexer system can transmit the same data rate as N standard systems in the volume of one transmission line.

[0104] In both systems, the protocol employs framing of the data (line coding, insertion of header with checksum, source and / or receive address, frame counter, scrambling, etc.), however, this framing may be part of the protocol or otherwise inserted by the transmit signal processor to optimize operation independent of existing user-specific or standardized protocols.

[0105] Figure 3 A system with 4 rings and 4 sections per ring is shown.

[0106] Each (ring) transmission line 210 comprises at least 2 transmission line segments 211, 212, 213, 214, each connected to a transmitter, in this FIG4, four ring transmission lines 210, 220, 230, 240 are shown, each ring transmission line having four transmission line segments. Each arc-shaped transmission line segment is connected to a transmitter "Tx". The signal is received by a receiving coupler 311, 312, 313, 315, as shown by the short arc-shaped segments, there is one more receiving coupler than the transmission line segment. Each receiving coupler is connected to a receiver "Rx". Multiple ring transmission lines can be stacked, in this case four 210, 220, 230, 240.

[0107] Figure 4 consists of three parts: Figure 4a , Figure 4b and Figure 4c Figure 4 shows a block diagram of one embodiment. Figure 4a An enlarged portion of the first body "rotor plate" is shown. Figure 4b An enlarged "slip ring" ("GigaCAP HD slip ring") is shown. Figure 4c An enlarged portion of the second body "stator plate" is shown.

[0108] On the first body (rotor), a transmit signal processor 400 is shown with: an interface "rotor interface", which may be part of a "rotor FPGA", connected to a rotor device generating data (e.g. a detector in a CT scanner); a transmit signal processor ("rotor-IP-core"), which employs framing of the data (line coding, header insertion with checksum, source and / or reception address, frame counter, scrambling, etc.), in any case this framing may be part of the protocol or otherwise inserted by the transmit signal processor to optimize operation independent of existing user-specific or standardized protocols. There may be an optoelectronic converter, which may be according to the QSFP standard (Quad Small Form-factor Pluggable), or any other suitable type.

[0109] As in Figure 3 The rotation-dependent multiplexer described in can be used for transmission. Figure 3 The system shown in FIG. 1 with 4 rings and 4 parts per ring can be used to connect a first body to a second body.

[0110] On the second body (stator), the receive signal processor 500 is shown with: an interface ("Stator Interface"), which can be part of a "Stator FPGA", connected to a stator device that evaluates the data (e.g., a storage or reconstruction processor of a CT scanner); a receive signal processor ("Stator-IP-Core") that evaluates the framing of the data reconstruction or removes corrupted information, removes corrupted information, and, if necessary, sorts or demultiplexes the data streams multiplexed to different receivers by evaluating the addresses contained in the frames. If the transmit signal processor inserts framing only for data transmission, the framing can be removed.

[0111] Figure 5 High-level diagnostic measures and benefits are shown.

[0112] Measures: Frame losses and inter-frame gaps can be sorted by transmitter and receiver and displayed as an error or state matrix. Thus, it allows the fitness level of each transmitting and receiving component for each transmission line to be calculated.

[0113] The interframe gap may be counted in interframe gaps (incremented by 1 regardless of the number of frames) and / or the width may be counted by counting lost frames.

[0114] The transmit frame counter ("NRx") and receive frame counter ("NTx") can be used to build a frame loss matrix. This can also identify transmission gaps. This only works if there is a valid count. There may be a permanent transmission control ("permanent tx protocol") to evaluate the effective count rate. The software encoder can be based on the effective count rate and can provide a coarse resolution NRx*NTx and a fine resolution by interpolation, for example, if the rotation speed is less than the minimum speed (speed>RPMmin).

[0115] Benefit: It can be displayed in real time, allowing for quick and real-time testing during assembly, quickly assessing improvements, for example if the receiver or connecting cables or fibers are aligned or replaced by factory or service personnel.

[0116] Service logs can be used to evaluate trends or occasional errors.

[0117] Status or error information may be compared to known conditions to allow the service software to propose corrective work actions or further testing.

[0118] The fitness score may show the NRx+NTx score (0..100%), which in the case of service can be used to identify "bad parts" or can be used to monitor system conditions. A real-time reception matrix may be useful for system startup to determine which path is actually feasible?

[0119] Figure 6 The frame counts of frames transmitted from two transmitters (TX0, TX1) to one receiver (RX0) are shown. When there is a gap in the frame count sequence and the source address (TX channel) is different, then this is most likely a regular transition. No loss or gap counter will be incremented. When there is a gap in the frame count sequence and the source address remains the same, then a frame is definitely lost. Therefore, the loss or gap counter will be incremented.

[0120] Thus, in the figure, a normal transition is depicted first (marked in green), and an error condition is depicted shortly thereafter (marked in red).

[0121] The diagnostics for the receiver or receiving channel detects the transitions by evaluating the source information in the frame. The receiver does not count the losses, the receiver interframe counter is incremented by a total of 3 so that the losses can be detected.

[0122] In error conditions, diagnostics are performed by evaluating the consecutive frame counters of the frames to detect the loss of the transmission channel.

[0123] Figure 7The frame numbers of frames transmitted from two transmitters (TX0, TX1) to two receivers (RX0, RX1) are shown. If the loss event occurs within a channel switch, the loss event cannot be clearly assigned to one receiving channel. This is called an ambiguous loss event. In the case of an ambiguous loss event, the frame gap counters of the two receiver channels involved (the fade-out channel and the fade-in channel) will be incremented. The loss counter of the transmitter will only be incremented once. In this case, there is a detected ambiguous frame, which increments the ambiguous frame counter of the transmitter, increases the two frame gap counters of the receivers involved, and the frame gap width counters of the two receivers are counted to 3, and the transmission loss counter is incremented by 5. Therefore, an error condition is described here, because 5 frames are lost, this is not a normal operating condition but an error condition.

[0124] Figure 8 One embodiment of a frame gap matrix is ​​shown, which may be part of the state matrix 900. The counters may be implemented as 64-bit counters. They may be considered life counters, since there are at most 1E6 frames per second (= 20 bits) and 3E13 frames per year (= 37 bits). However, the counters may be clipped at 0xFFFFFFFFFFFFFFFF to avoid wraparound. It may be advisable to reset the frame gap counters only at power-up, after the system has entered a known good state.

[0125] In order to analyze the exact interframe gap width, the RX data valid signal is read out via the angular position (encoder in the gantry setup). If there is no frame error, the RX data valid signal is 1.

[0126] The frame gap width, frame gap angle with respect to the rotation can be evaluated. The frame gap angle can be calculated with the help of a timer counter or by reading the encoder value.

[0127] The interframe gap can be evaluated based on the rotation speed, and the interframe gap and reception margin can be displayed per receiver. The reception margin is the difference between the actual interframe gap and the defined threshold value or the maximum interframe gap, which is the longest gap that can be tolerated without frame loss, meaning that no frames are lost because there is always at least one receiver synchronized on the data stream and receiving a valid signal containing at least a complete frame.

[0128] Fig. 9 A block diagram of another embodiment is shown.

[0129] On the first body (left side) and the second body (right side), a receive signal processor 500 ("RX IP") and a transmit signal processor 400 ("TX IP") plus a transceiver signal processor are shown.

[0130] The downlink (left to right direction) comprises a multiplexed capacitive transmission link having 2 transmission lines with 4 segments each, and the uplink of a standard capacitive transmission link having one transmission line with one transmission line segment. The uplink and downlink are each unidirectional, but can be combined to form a bidirectional link, as shown here.

[0131] In this case, an image data link is shown at a high data rate for the downlink, a lower data rate bidirectional control bus is multiplexed into the downlink in one direction, and a standard capacitive transmission link is used for the uplink in this embodiment.

[0132] Diagnostics may be implemented on each of the signal processors and the values ​​may be distributed via the bidirectional bus to a service computer connected to the static side of the system, for example, to the second body via the control bus.

[0133] The number of parts is specified by the suffix ("pc" or "pcs") for one piece or multiple pieces. Ethernet and EtherCAT are industrial communication / networking standards. Eth MAC stands for Ethernet MAC (Media Access Control). AXI4 is an interface standard (Advanced eXtensible Interface).

[0134] Reference Number List

[0135] 100 Rotary Capacitive Data Link System

[0136] 110 First Subject

[0137] 120 Second Subject

[0138] 130 Rotation axis

[0139] 150 Uplink

[0140] 151 Uplink Receiver

[0141] 152 Uplink Transmitter

[0142] 160 Controller

[0143] 210 First Ring Transmission Line

[0144] 211-214 The first transmission line section

[0145] 220 Second Ring Transmission Line

[0146] 221-224 Second transmission line section

[0147] 230 Third Ring Transmission Line

[0148] 231-234 The third transmission line section

[0149] 240 Fourth Ring Transmission Line

[0150] 241-244 Fourth transmission line segment

[0151] 310 first annular receiving coupler group

[0152] 311-315 First receiving coupler

[0153] 320 second ring receiving coupler group

[0154] 321-325 Second receiving coupler

[0155] 330 Third ring receiving coupler group

[0156] 331-335 Third receiving coupler

[0157] 340 fourth annular receiving coupler group

[0158] 341-345 Fourth receiving coupler

[0159] 400 Send signal processor

[0160] 410-413 Transmitter

[0161] 500 Receive Signal Processor

[0162] 510-514 Receiver

[0163] 900 Error or state matrix

[0164] 910 Data Field

Claims

1. A rotary capacitive data link system (100), comprising a first body (110) rotatable relative to a second body (120) about a rotation axis (130), The first body (110) comprises at least one annular signal transmission line (210, 220, 230), and each of the at least one annular signal transmission line (210, 220, 230) comprises at least two transmission line segments (211-214, 221-224, 231-234), and at least one mechanical gap is provided between the at least two transmission line segments (211-214, 221-224, 231-234). The second body (120) comprises at least one annularly arranged receiving coupler group (310, 320, 330), each receiving coupler group (310, 320, 330) comprising at least two receiving couplers (311-315, 321-325, 331-335) arranged circumferentially around the rotating shaft (130), Each of the receiving coupler groups (310, 320, 330) is capacitively coupled to one of the annular signal transmission lines (210, 220, 230), so that, according to the relative rotational position or angle between the first body (110) and the second body (120), a plurality of capacitive coupling paths exist between the transmission line segments (211-214, 221-224, 231-234) of each annular signal transmission line (210, 220, 230) and the receiving couplers (311-315, 321-326, 331-336) of the matching receiving coupler groups (310, 320, 330), Each of the receiving couplers (311-316, 321-326, 331-336) is connected to a receiving signal processor (500) at the second body (120), It is characterized in that The receive signal processor (500) is further configured to provide at least one error or state matrix (900), the error or state matrix (900) comprising at least one data field (910) for each combination of transmission line segments (211-214, 221-224, 231-234) and receive couplers (311-315, 321-325, 331-335) of each ring signal transmission line and its matched receive coupler group, wherein the at least one data field (910) is configured to contain at least one of an error and / or state indication value.

2. The data link system (100) according to claim 1, Wherein the at least one error or state matrix (900) is provided in real time.

3. The data link system (100) according to claim 1 or 2, Each of the transmission line segments (211-214, 221-224, 231-234) is connected to a transmission signal processor (400) at the first body, and the transmission signal processor (400) is configured to repack a protocol adding at least one of the following: a frame counter value, a source address and a transmission channel address, and / or The transmit signal processor (400) is configured to scramble the protocol.

4. The data link system (100) according to any one of the preceding claims, wherein the at least one error or state matrix (900) includes a row for each transmission line segment (211-214, 221-224, 231-234) and a column for each receiving coupler (311-315, 321-325, 331-335), or a column for each transmission line segment (211-214, 221-224, 231-234) and a row for each receiving coupler (311-315, 321-325, 331-335).

5. The data link system (100) according to any one of the preceding claims, A controller is provided, the controller being configured to evaluate the error or state matrix (900) and provide an error or state indication and / or provide reconfiguration of a transmit signal processor (400) and / or a receive signal processor (500) based on the data field (910) value.

6. The data link system (100) according to any one of the preceding claims, Therein, the controller stores error or status indicators at defined time intervals or after changes.

7. The data link system (100) according to claim 5, The controller collects error or status information of at least one receiving signal processor (500) and at least one transmitting signal processor (400) and / or a transceiver signal processor (500) that combines a transmitting signal processor (400) and a receiving signal processor (500), and the controller communicates with at least one of the processors (400, 500) via a multiplexed and / or non-multiplexed capacitive link system.

8. The data link system (100) according to any one of the preceding claims, The transmit signal processor (400) is configured to convert at least one data stream of a user channel into at least one of a plurality of parallel data streams transmitted through the plurality of capacitive coupling paths, and the receive signal processor (500) is configured to assemble the plurality of data streams back into the at least one data stream of the user channel.

9. The data link system (100) according to claim 6, wherein at least one transceiver signal processor of said first body aggregates bidirectional bus signals, combining uplink user channels and downlink user channels, The transceiver signal processor includes at least one of the one-way user channels of the receive signal processor (500) and at least one of the one-way user channels of the transmit signal processor (400), at least one transceiver signal processor of the second body aggregates bidirectional bus signals, An uplink user channel and a downlink user channel are combined, the transceiver signal processor comprising at least one of the unidirectional user channels of a receive signal processor and at least one of the unidirectional user channels of a transmit signal processor (400).

10. The data link system (100) according to the preceding claim, wherein the transmit signal processor comprises a separate transmitter (410-413) connected to each of the transmission line segments, and the receive signal processor comprises a separate receiver (510-513) connected to each of the receive couplers.

11. The data link system (100) according to any one of the preceding claims, The first body (110) further includes an uplink receiver (151), which matches the uplink transmitter (152) of the second body (120) and is configured to transfer data from the second body (120) to the first body (120).

12. The data link system (100) according to any one of the preceding claims, The error or state matrices for uplink and downlink can be separate, or can be combined in one multi-dimensional matrix.

13. A method for status assessment of a rotating capacitive data link system according to any one of the preceding claims, the system comprising at least one ring-shaped transmission line having at least two transmission line sections (211-214, 221-224, 231-234) capacitively coupled to at least two receiving couplers (311-315, 321-325, 331-335), the method comprising the following steps: An error or state matrix is ​​generated, the error or state matrix including at least one data field (910) for each matching combination of transmission line segments (211-214, 221-224, 231-234) and receive couplers (311-315, 321-325, 331-335), wherein the at least one data field (910) is configured to contain at least one of an error and / or state indication value.

14. A method for status assessment of a rotating capacitive data link system according to any one of the preceding claims.

Images