A ripple carrier based slave communication system and method

Abstract

The application discloses a kind of based on ripple carrier slave station communication system and method.The system includes at least one shared communication bus and at least two slave station devices connected thereto.The core is that each slave station device contains processing unit, with the ability to generate, send and demodulate carrier signal automatically, thereby realizing direct peer-to-peer communication independent of master station device.Using the attenuation characteristics inherent in transmission line of high frequency carrier signal, the effective propagation distance of signal is physically limited, naturally forming a "ripple" shaped communication area centered on the sending slave station.Slave stations located within the area can receive and respond to instructions, while slave stations outside the area are not affected.The application realizes intelligent, efficient local communication based on physical distance, significantly reduces system latency and dependence on central node, and is particularly suitable for industrial automation, distributed sensor network and other scenarios that require high real-time and reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of signal communication, in particular, and particularly relates to a slave communication system and method based on ripple carrier. BACKGROUND

[0002] In the field of industrial automation, building control, smart grid, etc., master-slave bus structure is widely used. In such systems, all slave devices are connected to a shared bus and controlled by a master device. Communication must be initiated by the master, which polls or calls specific slaves, and slaves can only respond after receiving instructions. Data exchange between all slaves must pass through the master.

[0003] This architecture has inherent defects: all communication must pass through the master, and when the number of slaves increases or frequent data exchange between slaves is required, the master becomes a communication bottleneck and system latency increases. When a slave needs to communicate with another slave, it must wait for the master to poll it before reporting data to the master, and the master then issues instructions to the slave, resulting in a long response chain that cannot meet the requirements of high real-time applications. Once the master fails, the entire system's communication will be paralyzed.

[0004] Therefore, there is an urgent need for a new bus system that enables direct, efficient and reliable communication between slaves. SUMMARY

[0005] Based on the deficiencies of the prior art, to solve the problem that existing slaves cannot directly communicate, the present application provides a slave communication system based on ripple carrier, comprising: at least one shared communication bus; at least two slave devices electrically connected to the shared communication bus; wherein each slave device comprises: a processing unit for generating and sending a carrier signal to the shared communication bus, and the processing unit of other slave devices receives the carrier signal for demodulation communication; the processing unit adjusts the effective communication distance of the slave device by controlling the frequency of the carrier signal, forms a ripple-shaped communication area of the effective communication distance around the slave device sending the carrier signal, and only other slave devices located within the ripple-shaped communication area can effectively communicate.

[0006] Optionally, the slave device communication in the ripple-shaped communication area does not interfere with the communication of other slave devices not in the ripple-shaped communication area.

[0007] Optionally, at least two slave devices are connected to one shared communication bus.

[0008] Optionally, the frequency of the carrier signal is inversely proportional to the effective communication distance between the slave devices, high-frequency signals attenuate quickly and have short communication distances, and low-frequency signals are the opposite.

[0009] The embodiment of the present application also proposes a slave station communication method based on ripple carrier, comprising the following steps: a processing unit in a first slave station device generates a carrier signal of a corresponding frequency; the first slave station device sends the carrier signal to the shared communication bus; a processing unit in a second slave station device receives the carrier signal from the shared communication bus; and the processing unit of the second slave station device demodulates the carrier signal for communication.

[0010] The present application has the following advantages:

[0011] 1. Peer-to-peer communication is realized: slave station devices can directly communicate without the mediation of a master station, which greatly reduces communication delay and lightens the load of the master station.

[0012] 2. System reliability and flexibility are improved: the dependence on single-point failure of the master station is reduced, and the communication topology is more flexible.

[0013] 3. Flexibility and scalability: single-bus and multi-bus architectures are supported, which can adapt to different scales and complexity of application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which are included to provide a further understanding of the present application, constitute a part of the present application and illustrate the illustrative embodiments of the present application and their description serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0015] Figure 1 is a system structure diagram of the embodiment of the present application and a comparison diagram with prior art;

[0016] Figure 2 is a single-bus multi-slave station communication topology diagram of one embodiment of the present application;

[0017] Figure 3 is a multi-bus multi-slave station communication topology diagram of another embodiment of the present application;

[0018] Figure 4 is a communication range topology diagram of multi-bus multi-slave station communication in yet another embodiment of the present application.

[0019] Among the above drawings, the following reference signs are included:

[0020] 1 - shared communication bus, 2 - slave station device, 3 - master station device, 4 - MCU (Microcontroller Unit), 5 - carrier signal. DETAILED DESCRIPTION

[0021] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor should be within the scope of protection of the present application.

[0022] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or apparatus including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or apparatuses.

[0023] Figure 1 A kind of based on ripple carrier slave communication system structure diagram and comparison chart with prior art, in the system, including at least n slave device 1 and at least m shared communication bus 2, wherein m is greater than or equal to 1 Positive integer, n is greater than or equal to 2 Positive integer.Each shared communication bus is hung with at least 2 slave devices, for realizing the direct communication of slave device directly.

[0024] In the embodiments of the present application, the slave device is specifically a sensor, and can also be other slave devices, without specific limitation. Each sensor is internally integrated with a processing unit, which is specifically an MCU 4 in the present application, without specific limitation. The MCU in the sensor generates and sends a sinusoidal carrier signal 5 to the shared communication bus, and the frequency of the carrier signal is set to f. In addition, other sensors that need to communicate with each other receive the carrier signal transmitted on the shared communication bus through the MCU therein, and convert it into a digital signal through the MCU, so as to achieve the purpose of communication between two sensors.

[0025] In addition, in Figure 1 The prior art master-slave station communication is also shown in the figure. The shared communication bus is hung with a master station device 3. When the slave devices need to communicate with each other, the slave devices need to collect data information first, and then send it to the master station device through the shared communication bus. The master station device sends instructions to other slave devices through the shared communication bus, so as to realize the communication between the slave devices.

[0026] Compared with the prior art, in an embodiment of the present application, the principle of direct communication between slave devices includes: when sensor 1 needs to communicate with sensor 2, the MCU in sensor 1 sends a carrier signal with a frequency of f onto the bus, and the specific principle of transmitting the carrier signal onto the shared communication bus for transmission includes:

[0027] First, the propagation of the original signal on the bus follows the telegraph equation formula (1):

[0028] (1)

[0029] Where U(x, t) and I(x, t) represent the voltage and current at position x and time t, respectively, R, L, G, and C are the distributed resistance, distributed inductance, distributed conductance, and distributed capacitance per unit length.

[0030] The propagation constant in the telegraph equation can be calculated as formula (2):

[0031] γ = α + jβ = (2)

[0032] Where α is the attenuation constant and β is the phase constant.

[0033] The amplitude of the electromagnetic wave propagating along the bus decreases exponentially with distance, and the signal amplitude attenuation is formula (3):

[0034] (3)

[0035] Where V0 is the initial amplitude, α is the attenuation constant, and d is the transmission distance. As long as V(d) is higher than the receiving sensitivity V min , other sensors can receive the signal.

[0036] Therefore, in the embodiment of the present application, after the slave device transmits the sinusoidal carrier signal V(x)e jωt , according to the design relationship between frequency and distance, under high frequency conditions (ωL≫R and ωC≫G), the propagation constant can be simplified as formula (4):

[0037] (4)

[0038] At this time, the attenuation constant is formula (5):

[0039] (5)

[0040] Considering the effect of skin effect, the distributed resistance R is proportional to the square root of the frequency: R∝ Therefore, the attenuation constant can be further expressed as equation (6):

[0041] (6)

[0042] wherein 、 is a constant related to the cable material and structure.

[0043] To ensure reliable communication, equation (7) must be satisfied:

[0044] (7)

[0045] Solving the above inequality, the maximum communication distance formula (8) when the carrier signal frequency is f can be obtained:

[0046] (8)

[0047] According to the above formula, when slave station 1 sends a carrier signal with a frequency of f, all slave stations within the range of the ripples around slave station 1 and at a distance of d or less can receive the signal and communicate.

[0048] wherein, the communication between the slave station devices within the current range and the slave station devices outside the current distance range do not interfere with each other.

[0049] In another embodiment, the distribution of slave stations is as shown in Figure 2 A communication bus is mounted with slave station 1, slave station 2, …, slave station n at equal intervals on both sides, each slave station is built-in with MCU and has carrier modulation and demodulation capability.

[0050] When slave station 3 needs to communicate with other slave stations, the MCU in slave station 3 sends a carrier signal with a frequency of f. According to the above formula, the signal attenuates in both directions along the bus.

[0051] Only the slave stations with a physical distance d≤d max from slave station 3, such as slave station 2 and slave station 4, can communicate with slave station 3 because their distances d 32 , d 34 from slave station 3 are less than the maximum communication distance d max ; while the slave stations 1 and 5~n that are far away cannot demodulate the signal because it has attenuated to the maximum communication distance d max , and thus cannot communicate with other slave stations. The ripple range of this communication is the bus area from slave station 2 to slave station 4, and the instructions of slave station 3 only take effect in this local range. It is suitable for segmented control of large equipment (such as automated production lines and intelligent light strips), which can realize precise operation on a specific area without the intervention of master station devices or interference with other areas.

[0052] In another embodiment, the distribution of slave stations is as follows: Figure 3 As shown, multiple shared communication buses are connected to slave station 1, and each shared communication bus is connected to a slave station. Slave station 1 is the core node of the system. It integrates an MCU and has strong processing capabilities. It is connected to slave station 2...slave station n-1 and slave station n through multiple independent physical buses. Each slave station is connected to slave station 1 through a bus.

[0053] Under this architecture, the physical distance d from slave station 1 is ≤ d max The distance d between slave stations, such as slave station 1 and slave station 2... slave station n-1, and slave station n. 12 ......d 1n-1 d 1n All are at the current ripple distance d max Within this range, based on the carrier demodulation capability of the MCU in the slave station, communication between slave station 1 and other slave stations can be achieved.

[0054] Therefore, based on the communication reliability calculation of the distance between slave station 1 and other slave stations, accurate and predictable ripple communication is achieved.

[0055] In yet another embodiment, the distribution of slave stations is as follows: Figure 4 As shown, there are n slave stations, which are unevenly distributed. Slave stations 4 and 9 are connected to multiple shared communication buses. It should be noted that slave stations 4, 5, ... 8 are all connected to a single shared communication bus.

[0056] When station 4 transmits a carrier signal with frequency f, the maximum communication distance is calculated as d according to the above formula. max When the distance between slave stations 1 to 3, slave stations 5 to 9, and slave station 4 on the corresponding bus is specifically d 41 d 42 ......d 49 All are less than the maximum communication distance d max At this time, slave station 1 can communicate with slave stations 1 to 3 and slave stations 5 to 9 within the current ripple range.

[0057] However, when the distance d between station 4 and station 10 is... 410 It is also less than d max However, since slave station 4 and slave station 10 are not connected by a shared communication bus, they cannot communicate directly with slave station 10.

[0058] Therefore, when the physical distance from the slave station exceeds d... maxand the slave station not connected with the current slave station on the same bus and out of the communication range cannot communicate with each other.

[0059] In summary, the MCU in the slave station device generates and sends the carrier signal, under the carrier signal of the corresponding frequency, the other slave station devices in the maximum effective communication distance ripple area range and connected with the current slave station device through the shared communication bus can directly communicate with the current slave station device, avoiding the communication through the master station as a relay, and improving the communication efficiency.

[0060] The above sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0061] In the above embodiments of the present application, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0062] In the several embodiments provided by the present application, it should be understood that the disclosed technology can be implemented in other ways. Of course, the device embodiment described above is only schematic. Depending on the division of the functions of the units, some units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or communication connection between units can be indirect coupling or communication connection through some interface, unit or module, and can be electrical or other forms.

[0063] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment.

[0064] The above only describes the preferred embodiments of the present application. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, some improvements and refinements can be made, which should also be considered as the protection scope of the present application.

Claims

1. A ripple carrier based slave communication system, characterized by, The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. ； wherein V0 is an initial amplitude of the carrier signal, a is an attenuation constant, and d is the effective communication distance, is a signal amplitude of the carrier signal after transmitting the effective communication distance d. When the slave device transmits the carrier signal with a frequency of f, the effective communication distance is within the maximum effective communication distance range, and the formula of the maximum effective communication distance is as follows: ； wherein is the maximum effective communication distance of the slave device transmitting the carrier signal, f is the frequency of the carrier signal, is the minimum reception sensitivity of the carrier signal.

2. The slave communication system according to claim 1, characterized by The application relates to a slave communication method and a slave communication system.

3. The slave communication system according to claim 1, wherein The application relates to a slave communication method and a slave communication system.

4. A method for ripple carrier based slave communication, applied to the slave communication system according to any one of claims 1-3, characterized in that, The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave communication method and a slave communication system. The application relates to a slave

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