Imaging system with high electromagnetic compatibility

Abstract

The invention relates to the technical field of imaging systems, in particular to an imaging system with high electromagnetic compatibility, which comprises a distributor, a linear array focal plane group, an area array focal plane group, an imaging processor group, a laser group and a controller, and is characterized in that the distributor receives a primary power supply input from the outside and provides independent power supply of a secondary power supply for each device; the machine shell of each device is connected with the shielding ground of the corresponding cable, and meanwhile the machine shell of each device is connected with the cabin plate. The secondary ground in the distributor and the secondary ground in the laser group are not connected with the own shell; and the secondary ground in the linear array focal plane group, the secondary ground in the area array focal plane group, the secondary ground in the imaging processor group and the secondary ground in the controller are all in compression joint with own shells in a copper laying grounding mode. The electromagnetic compatibility of the imaging system can be improved, and mutual interference among all parts in the imaging system can be avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of imaging systems, and in particular relates to an imaging system with high electromagnetic compatibility performance. Background Art

[0002] The imaging system is usually treated as a floating ground system. The housing of each device in the imaging system is connected to the shielding ground of the corresponding cable, but the shielding ground of each cable is not directly connected to the signal ground. All the shielding grounds on each cable are connected to the signal ground at only one point. With the increase of operating frequency and the acceleration of transmission rate, signals with frequencies exceeding 1GHz begin to appear in the imaging system. It is necessary to perform multi-point grounding according to the high-frequency equipment. The housing of each high-frequency device is connected to the shielding ground of the corresponding cable, and the shielding ground of each cable is directly connected to the signal ground. When the housings of all high-frequency devices are connected to the signal ground, the high-frequency devices are connected together through secondary equipotential signals, the housings of each high-frequency device are connected to the cabin board, and the power supply equipment supplies power to each high-frequency device. In addition to providing secondary return lines, the power supply equipment also outputs telemetry voltage and telemetry return lines, which may cause the shunting of the return current of each power supply circuit, thereby causing mutual interference between the various parts in the imaging system. Summary of the invention

[0003] In view of this, the present invention aims to provide an imaging system with high electromagnetic compatibility performance to solve the problem of mutual interference among various parts in the imaging system caused by multi-point grounding of various high-frequency devices.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows: An imaging system with high electromagnetic compatibility performance comprises a power distributor, a linear array focal plane group, an area array focal plane group, an imaging processor group, a laser group and a controller; wherein the power distributor receives a primary power supply input from the outside, and provides an independent secondary power supply for the linear array focal plane group, the area array focal plane group, the imaging processor group and the controller; the controller communicates with the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group respectively, and receives telemetry signals returned by the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group; the controller controls the power distributor to control the power on and off of the linear array focal plane group, the area array focal plane group and the imaging processor group; the power distributor The casing of the device, the casing of the linear array focal plane group, the casing of the area array focal plane group, the casing of the imaging processor group, the casing of the laser group and the casing of the controller are all connected to the shielded ground of their corresponding cables, and at the same time, the casing of the distributor, the casing of the linear array focal plane group, the casing of the area array focal plane group, the casing of the imaging processor group, the casing of the laser group and the casing of the controller are all connected to the cabin plate; the secondary ground inside the distributor and the secondary ground inside the laser group are not connected to their own casings; the secondary ground inside the linear array focal plane group, the secondary ground inside the area array focal plane group, the secondary ground inside the imaging processor group and the secondary ground inside the controller are all crimped to their own casings through copper grounding.

[0005] Furthermore, an isolation transformer is used inside the distributor to isolate the external primary power supply from the output secondary power supply, and independently provide secondary power supply for the linear array focal plane group, the area array focal plane group, the imaging processor group and the controller. The power supply of the linear array focal plane group, the power supply of the area array focal plane group, the power supply of the imaging processor group and the power supply of the controller are not connected inside the distributor, and the secondary return line of the linear array focal plane group, the secondary return line of the area array focal plane group, the secondary return line of the imaging processor group, the secondary return line of the laser group and the secondary return line of the controller are not connected inside the distributor.

[0006] Furthermore, telemetry signals returned to the controller by the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group are transmitted using a photoelectric isolation device.

[0007] Furthermore, the optoelectronic isolation device includes a matching optoelectronic transmitting device and an optoelectronic receiving device. The linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group respectively send their own telemetry signals through independent optoelectronic transmitting devices, and the controller receives each telemetry signal through the optoelectronic receiving device corresponding to each optoelectronic transmitting device.

[0008] Furthermore, the secondary ground inside the laser group is not connected to the secondary ground inside the controller.

[0009] Furthermore, the controller includes a control logic circuit and a focus motor; wherein, One connection method between the control logic circuit and the focus motor is: the signal of the control logic circuit and the signal of the focus motor are transmitted using a photoelectric isolation device, and the secondary ground inside the control logic circuit is not connected to the secondary ground inside the focus motor; Another connection method between the control logic circuit and the focus motor is: the signal of the control logic circuit is connected to the signal of the focus motor for transmission, the secondary ground inside the control logic circuit is connected to the secondary ground inside the focus motor, and the focusing and imaging work in a time-sharing manner.

[0010] Furthermore, a secondary loop in the distributor for supplying power to the linear array focal plane group, the area array focal plane group, the imaging processor group, the laser group and the controller is connected to the secondary ground inside the controller through a series resistor.

[0011] Furthermore, the resistance of the series resistor Select by: ; In the formula, R is the resistance value of the secondary circuit in the distributor. is the noise voltage threshold for stable signal transmission, is the inductive reactance of the transmission line, and I is the maximum current value in the secondary return current of the linear array focal plane group, area array focal plane group, imaging processor group, laser group and controller.

[0012] Furthermore, the key signals output by the controller are driven by the OC gate drive circuit, and the key signals are connected to their respective secondary power supplies using pull-up resistors at the linear array focal plane group, the area array focal plane group, and the imaging processor group ends. At the same time, the key signals are connected to their respective internal secondary grounds using grounding capacitors at the linear array focal plane group, the area array focal plane group, and the imaging processor group ends.

[0013] Compared with the prior art, the invention can achieve the following beneficial effects: (1) The housings of the power distributor, linear array focal plane group, area array focal plane group, imaging processor group, laser group and controller are all connected to the shielded ground of the corresponding cables and to the cabin board; the secondary ground inside the power distributor and laser group is not connected to their own housings; the secondary ground inside the linear array focal plane group, area array focal plane group, imaging processor group and controller is crimped to the housing through the copper grounding method on the circuit board, thereby improving the electromagnetic compatibility performance of the imaging system; (2) The telemetry signals from the linear array focal plane group, the area array focal plane group, the imaging processor group, and the laser group back to the controller are transmitted in a photoelectric isolation manner to avoid the conduction interference caused by connecting the signal grounds of each device together. This can effectively prevent the laser group with strong interfering pulsating current characteristics from interfering with the signals of other devices. (3) For stepper motor focusing devices with interference in the controller, one solution for connecting the control logic circuit and the focusing motor is to use photoelectric isolation to transmit signals, so as to avoid the signal ground of the control logic circuit and the focusing motor being connected together to cause conduction interference, and the secondary grounds between the control logic circuit and the focusing motor are not connected together; another solution for connecting the control logic circuit and the focusing motor is to directly connect the signal of the control logic circuit and the focusing motor, and the secondary grounds between the control logic circuit and the focusing motor are also connected together, but no imaging is performed during the focusing working stage, and no focusing is performed during the imaging working stage. By adopting a time-sharing working mode of focusing and imaging, interference of focusing on imaging is avoided; (4) For the possible shunt effect of the telemetry loop inside the distributor, photoelectric isolation or resistance separation is used to suppress or reduce the interference caused by the secondary return shunt; (5) Most signals are transmitted in differential form, single-ended signals are transmitted using resistor current limiting, and key signals are transmitted using RC integration circuits to reduce the impact of external interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 is a schematic structural diagram of an imaging system with high electromagnetic compatibility according to an embodiment of the invention; Figure 2 It is a schematic diagram of a grounding topology structure using photoelectric isolation according to an embodiment of the invention; Figure 3 It is a schematic diagram of a grounding topology structure using resistance isolation according to an embodiment of the invention; Figure 4 It is a schematic diagram of the structure of the RC integration circuit described in the embodiment of the invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0016] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0017] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0018] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0019] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0020] like Figure 1-Figure 4 As shown, the imaging system with high electromagnetic compatibility performance includes a distributor, a linear array focal plane group, an area array focal plane group, an imaging processor group, a laser group and a controller; wherein the distributor receives an external primary power supply to provide independent secondary power supply for the linear array focal plane group, the area array focal plane group, the imaging processor group and the controller; the laser group independently receives an external primary power supply to generate a related secondary power supply to power related internal circuits; the controller receives an external primary power supply to generate a related secondary power supply to power related internal circuits, such as a control logic The controller controls the power supply of the circuit, the power supply of the focusing motor, etc.; the control logic circuit inside the controller communicates and controls with the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group respectively, performs relevant timing coordination, and receives the telemetry signals returned by the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group; the controller controls the power supply of the linear array focal plane group, the area array focal plane group and the imaging processor group on and off by controlling the distributor; the laser group generates an instantaneous laser pulse, which is projected to the area array focal plane group after reflection to detect the laser footprint.

[0021] In a specific embodiment of the present invention, (1) the distributor adopts the DCDC product of 510 Institute; (2) the linear array focal plane group and the area array focal plane group adopt the linear array detector and the area array detector of Changguang Chenxin Company and the FPGA chip of Fudan Microelectronics Company; (3) the imaging processor group adopts the FPGA chip of Fudan Microelectronics Company; (4) the laser group adopts the product of Shanghai Institute of Optics and Fine Mechanics; (5) the control logic part of the controller adopts the FPGA of Fudan Microelectronics Company, and the focusing motor adopts a stepping motor.

[0022] The casing of the distributor, the casing of the linear array focal plane group, the casing of the area array focal plane group, the casing of the imaging processor group, the casing of the laser group and the casing of the controller are all connected to the shielded ground of their respective corresponding cables through grounding piles, and at the same time, the casing of the distributor, the casing of the linear array focal plane group, the casing of the area array focal plane group, the casing of the imaging processor group, the casing of the laser group and the casing of the controller are all connected to the cabin board; the secondary ground inside the distributor and the secondary ground inside the laser group are not connected to their own casings; the secondary ground inside the linear array focal plane group, the secondary ground inside the area array focal plane group, the secondary ground inside the imaging processor group and the secondary ground inside the controller are all crimped together with their own casings through a large-area copper grounding method on the circuit board. Through the above settings, the electromagnetic compatibility performance of the imaging system is improved.

[0023] In order to prevent the possible shunt effect on the internal telemetry loop of the distributor, photoelectric isolation or resistor isolation is used to suppress or reduce the interference caused by the secondary return shunt.

[0024] The grounding topology using opto-isolation is as follows Figure 2 As shown, there are m independent linear array focal planes in the linear array focal plane group, n independent imaging processors in the imaging processor group, and q independent area array focal planes in the area array focal plane group. Each linear array focal plane, area array focal plane, and imaging processor is a module. An isolation transformer is used inside the distributor to isolate the external input primary power supply from the output secondary power supply, and each module is powered independently. The power supply of each module is not connected inside the distributor, and the secondary return line of each module is not connected inside the distributor. The telemetry signal returned by each module to the controller through the distributor is transmitted by photoelectric isolation.

[0025] The photoelectric isolation method is realized through a photoelectric isolation device. The photoelectric isolation device includes a matching photoelectric transmitting device and a photoelectric receiving device. The linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group respectively send their own telemetry signals through independent photoelectric transmitting devices, and the controller receives each telemetry signal through the photoelectric receiving device corresponding to each photoelectric transmitting device.

[0026] Low-cost grounding topologies using resistive isolation such as Figure 3As shown, the distributor and the controller are combined into one electrical box device, collectively referred to as the controller. The original controller is called the controller control part, and the original distributor is called the controller power supply and distribution part. The controller power supply and distribution part supplies power to all parts except the laser group. There are m independent linear array focal planes in the linear array focal plane group, n independent imaging processors in the imaging processor group, and q independent area array focal planes in the area array focal plane group. Each linear array focal plane, area array focal plane, and imaging processor are all modules. An isolation transformer is used inside the controller power supply and distribution part to isolate the external input primary power supply from the output secondary power supply, and power each module independently. The power supply of each module has no connection relationship inside the distributor, and the secondary return line of each module has no connection relationship inside the distributor; the secondary return line in the controller power supply and distribution part that supplies power to each group of linear array focal planes, each group of area array focal planes, and each group of imaging processors is connected to the secondary ground of the controller control part through a series resistor.

[0027] The resistance of the series resistor The choice of depends on the maximum current value I in the secondary return of each module, the resistance value R of the secondary return line in the power supply and distribution part of the controller, and the noise voltage threshold for stable signal transmission. , the inductive reactance of the transmission line , as follows: .

[0028] For laser groups with pulsating current characteristics with strong interference, the telemetry signal of the laser group is photoelectrically isolated from the telemetry signals of other devices to avoid conduction interference caused by connecting the signal grounds together. The secondary ground of the laser group is not connected to the secondary ground of the controller.

[0029] For a stepper motor focusing device with interference in the controller, one scheme for connecting the control logic circuit and the focusing motor is to transmit the signal of the control logic circuit and the signal of the focusing motor by means of photoelectric isolation (implemented by a photoelectric isolation device) to avoid conduction interference caused by connecting the signal grounds together, and the secondary ground inside the control logic circuit is not connected to the secondary ground inside the focusing motor; another scheme for connecting the control logic circuit and the focusing motor is to transmit the signal of the control logic circuit and the signal of the focusing motor by connecting them, and the secondary ground inside the control logic circuit is connected to the secondary ground inside the focusing motor, but no imaging is performed during the focusing working stage, and no focusing is performed during the imaging working stage, and interference of focusing on imaging is avoided by adopting a time-sharing working mode of focusing and imaging.

[0030] To prevent short-circuit faults between devices that may cause large currents and improve anti-interference capabilities, the differential telemetry signals output by the linear array focal plane group, the area array focal plane group, and the imaging processor group are transmitted in differential form; the single-ended telemetry signals output by the linear array focal plane group, the area array focal plane group, and the imaging processor group are not directly output through the power supply, but are limited by current in series with a resistor to ensure that the short-circuit current is at the milliampere level when the signal is short-circuited. Figure 4 As shown, the key signals output by the controller (such as the master-slave identification signals) are driven by the OC (open drain) gate drive circuit. The key signals are connected to the secondary power supply at the linear array focal plane group, the area array focal plane group, and the imaging processor group using pull-up resistors. At the same time, the key signals are connected to the secondary grounds of the linear array focal plane group, the area array focal plane group, and the imaging processor group using grounding capacitors. That is, the key signals are output using an RC integration circuit. When a short circuit occurs, the current limiting effect of the pull-up resistor can ensure that the short-circuit current is at the milliampere level when the signal is short-circuited. At the same time, the grounding capacitor can filter out possible interference on the transmission line.

[0031] When the controller detects that the current of the load in the distributor (including the linear array focal plane group, the area array focal plane group and the imaging processor group) exceeds 10% to 20% of the rated current, the distributor automatically performs current limiting protection measures and shuts off the output voltage; when the controller detects that the telemetry voltage in the distributor is abnormal, the power supply of the abnormal telemetry voltage group in the distributor (including the linear array focal plane group, the area array focal plane group and the imaging processor group) is shut down; when the controller detects that the operating temperature of the linear array focal plane group, the area array focal plane group and the imaging processor group exceeds the safe temperature threshold, the power supply of the abnormal temperature group in the distributor is shut down. By detecting the load current, telemetry voltage and operating temperature of each device of the distributor, the abnormal device can be quickly shut down to avoid affecting the other normal devices. When the laser group is abnormal, the current limiting protection measures are automatically and independently executed to shut down the output voltage.

[0032] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0033] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An imaging system with high electromagnetic compatibility performance, characterized in that: It includes a distributor, a linear array focal plane group, an area array focal plane group, an imaging processor group, a laser group and a controller; wherein, The distributor receives the primary power input from the outside, and provides the independent power supply of the secondary power supply to the linear array focal plane group, the area array focal plane group, the imaging processor group and the controller; the controller communicates with the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group respectively, and receives the telemetry signals returned by the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group; the controller controls the distributor to control the power on and off of the linear array focal plane group, the area array focal plane group and the imaging processor group; The casing of the distributor, the casing of the linear array focal plane group, the casing of the area array focal plane group, the casing of the imaging processor group, the casing of the laser group and the casing of the controller are all connected to the shielded ground of their corresponding cables, and at the same time, the casing of the distributor, the casing of the linear array focal plane group, the casing of the area array focal plane group, the casing of the imaging processor group, the casing of the laser group and the casing of the controller are all connected to the cabin plate; the secondary ground inside the distributor and the secondary ground inside the laser group are not connected to their own casings; the secondary ground inside the linear array focal plane group, the secondary ground inside the area array focal plane group, the secondary ground inside the imaging processor group and the secondary ground inside the controller are all crimped to their own casings through copper grounding.

2. The imaging system with high electromagnetic compatibility according to claim 1, characterized in that: An isolation transformer is used inside the distributor to isolate the external primary power supply from the output secondary power supply, and independently provide secondary power supply for the linear array focal plane group, area array focal plane group, imaging processor group and controller. The power supply of the linear array focal plane group, the power supply of the area array focal plane group, the power supply of the imaging processor group and the power supply of the controller are not connected inside the distributor, and the secondary return line of the linear array focal plane group, the secondary return line of the area array focal plane group, the secondary return line of the imaging processor group, the secondary return line of the laser group and the secondary return line of the controller are not connected inside the distributor.

3. The imaging system with high electromagnetic compatibility according to claim 1, characterized in that: The telemetry signals returned to the controller by the linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group are transmitted using photoelectric isolation equipment.

4. The imaging system with high electromagnetic compatibility according to claim 3, characterized in that: The photoelectric isolation device includes a matching photoelectric transmitting device and a photoelectric receiving device. The linear array focal plane group, the area array focal plane group, the laser group and the imaging processor group respectively send their own telemetry signals through independent photoelectric transmitting devices, and the controller receives each telemetry signal through the photoelectric receiving device corresponding to each photoelectric transmitting device.

5. The imaging system with high electromagnetic compatibility according to claim 3, characterized in that: The secondary ground inside the laser group is not connected to the secondary ground inside the controller.

6. The imaging system with high electromagnetic compatibility according to claim 4, characterized in that: The controller includes a control logic circuit and a focus motor; wherein, One connection method between the control logic circuit and the focus motor is: the signal of the control logic circuit and the signal of the focus motor are transmitted using a photoelectric isolation device, and the secondary ground inside the control logic circuit is not connected to the secondary ground inside the focus motor; Another connection method between the control logic circuit and the focus motor is: the signal of the control logic circuit is connected to the signal of the focus motor for transmission, the secondary ground inside the control logic circuit is connected to the secondary ground inside the focus motor, and the focusing and imaging work in a time-sharing manner.

7. The imaging system with high electromagnetic compatibility according to claim 2, characterized in that: The secondary return line in the distributor for supplying power to the linear array focal plane group, the area array focal plane group, the imaging processor group, the laser group and the controller is connected to the secondary ground inside the controller through a series resistor.

8. The imaging system with high electromagnetic compatibility according to claim 7, characterized in that: The resistance of the series resistor Select by: ； In the formula, R is the resistance value of the secondary circuit in the distributor. is the noise voltage threshold for stable signal transmission, is the inductive reactance of the transmission line, and I is the maximum current value in the secondary return current of the linear array focal plane group, area array focal plane group, imaging processor group, laser group and controller.

9. The imaging system with high electromagnetic compatibility according to claim 1, characterized in that: The key signals output by the controller are driven by the OC gate drive circuit. The key signals are connected to their respective secondary power supplies using pull-up resistors at the linear array focal plane group, area array focal plane group, and imaging processor group ends. At the same time, the key signals are connected to their respective internal secondary grounds using grounding capacitors at the linear array focal plane group, area array focal plane group, and imaging processor group ends.

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