Motor vehicle digital base system based on composite bus

Abstract

The invention provides a motor vehicle digital base system based on a composite bus, and relates to the technical field of motor vehicle control, the motor vehicle digital base system comprises the composite bus, the composite bus comprises a main bus and a local one-way SIF data line, the main bus adopts a quasi-duplex communication mode, bidirectional data transmission is realized through a single signal line, and the signal line adopts a higher-level reversed-polarity UART (Universal Asynchronous Receiver / Transmitter) communication format; the local one-way SIF data line is used for transmitting state information of the motor controller to the rear control box; the control module group comprises input equipment, a front control box, a rear control box, an instrument and a motor controller; the main bus interfaces of the front control box and the rear control box are respectively provided with a transmit-receive circuit, and each transmit-receive circuit comprises a transmitting unit, a receiving unit and a protection unit. The technical problems that in the prior art, the number of wiring harnesses is large, manufacturing cost is high, voltage endurance capacity is low, maintenance is difficult, system cost is high, and expansibility is poor can be solved, a system integration scheme with high cost performance is achieved, and real-time performance of signal transmission and robustness of system operation are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of motor vehicle control, and particularly to a motor vehicle digital base system based on a composite bus. Background Art

[0002] In the field of in-vehicle wiring harness systems, the traditional single-wire direct connection point-to-point system wiring harness method is the most basic technical solution. In this method, loads such as lights or actuating components are directly controlled by switches, and status information is transmitted one-to-one through signal lines to indicating instruments. This solution requires more than 20 wiring harnesses to connect the front and rear parts of the vehicle, which not only increases the weight and cost of the whole vehicle, but also leads to complex assembly, difficult maintenance, and obvious deficiencies in terms of system scalability and integration.

[0003] With the development of automotive electronic technology, standard distributed bus systems (such as CAN and RS485, etc.) have gradually been widely used. Although such bus systems have advantages such as high data transmission rate and flexible networking, their voltage withstand capabilities are generally low. For example, non-isolated CAN and RS485 buses are only applicable to systems below 28V. However, in small vehicle systems such as two-wheelers and three-wheelers, due to the need to configure complex system isolation and other protection circuits to improve the voltage withstand capability, the hardware cost remains high, and the system reliability is also difficult to guarantee.

[0004] Currently, mainstream fuel motorcycles, electric two-wheelers, and three-wheelers on the market still generally adopt the traditional single-wire direct connection point-to-point system wiring harness method. This technical solution not only has problems such as a large number of wiring harnesses (more than 20) and complex layout, but also has obvious deficiencies in terms of function expansion, system integration, fault diagnosis, etc. At the same time, the existing technical solutions are also difficult to meet the growing market demand in terms of voltage withstand capability (generally lower than 28V), system reliability, and cost-effectiveness. Therefore, there is an urgent need to develop a vehicle wiring harness bus connection technology with both reliability and cost advantages. Summary of the Invention

[0005] In view of this, the present invention proposes a motor vehicle digital base system based on a composite bus. The system aims to solve the technical problems in the prior art such as a large number of wiring harnesses, complex connections, high manufacturing costs, low voltage withstand capabilities, difficult maintenance, high system costs, and poor scalability. Through the composite bus architecture design and a reliable transceiver circuit protection mechanism, a high-cost-effective system integration solution is realized, while ensuring the real-time nature of signal transmission, the reliability, and robustness of system operation, so as to meet the actual application requirements of small vehicles such as two-wheelers and three-wheelers.

[0006] The technical solution of the present invention is realized as follows:

[0007] The present invention provides a motor vehicle digital base system based on a composite bus, including:

[0008] The composite bus includes a main bus and a local unidirectional SIF data line, where: the main bus adopts a quasi-duplex communication mode to achieve bidirectional data transmission through a single signal line, and the signal line adopts a high-level reverse-polarity UART communication format; the local unidirectional SIF data line is used to transmit the status information of the motor controller to the rear control box.

[0009] The control module group includes an input device, a front control box, a rear control box, an instrument, and a motor controller, where:

[0010] The input device includes a left combination switch and a right combination switch, which are used to implement P gear control and other input control functions;

[0011] The front control box is electrically connected to the input device, and is used to receive and process control signals, and send control instructions through the main bus;

[0012] The rear control box is connected to the front control box through the main bus, and is used to control the rear load, receive the motor status information transmitted by the local unidirectional SIF data line, and forward it to the main bus;

[0013] The instrument is electrically connected to the main bus through a power line, a ground line, and a signal line, and is used to display system status information;

[0014] The motor controller is used to read the control instructions on the main bus and execute corresponding power output control, and at the same time send the status information of the motor to the rear control box through the local unidirectional SIF data line;

[0015] Transceiver circuits are provided at the main bus interfaces of the front control box and the rear control box, which are used to realize signal transmission and reception. The transceiver circuit includes a sending unit, a receiving unit, and a protection unit.

[0016] On the basis of the above solution, preferably, the sending unit of the transceiver circuit includes a constant-current source circuit and a voltage-limiting circuit:

[0017] The constant-current source circuit is composed of a transistor Q9 and its bias resistors, and is used to limit the output current;

[0018] The voltage-limiting circuit is composed of a diode DW15V, and is used to limit the output voltage within fifteen volts;

[0019] The sending unit further includes an input resistor R76 and bias resistors R02 and R70, where the input resistor R76 is used to receive control signals, and the bias resistors R02 and R70 are used to set the operating point of the constant-current source.

[0020] On the basis of the above solution, preferably, the receiving unit of the transceiver circuit includes an input-stage circuit and a filtering circuit:

[0021] The input stage circuit consists of transistor Q62 and its biasing resistors, and adopts a low-impedance design;

[0022] The filtering circuit consists of capacitor C60 and is used to filter out interference signals;

[0023] The receiving unit further includes a pull-up resistor R67 for providing a signal reference level.

[0024] Based on the above solution, preferably, the protection unit of the transceiver circuit includes a high-voltage protection circuit and an over-current protection circuit:

[0025] The high-voltage protection circuit consists of diode DT1 and resistor RT4 and can withstand a voltage of one hundred volts;

[0026] The over-current protection circuit realizes current limitation through the cross-current source circuit;

[0027] The protection unit further includes an anti-interference circuit, which is realized through low-impedance design and filtering capacitors.

[0028] Based on the above solution, preferably, the left combination switch and the right combination switch in the input device are configured with a P gear control function; the front control box includes:

[0029] A turn signal control unit for processing turn signal control signals from the input device;

[0030] A transceiver circuit for sending the processed control signals to other modules through the main bus.

[0031] Based on the above solution, preferably, the rear control box includes:

[0032] A load control unit for controlling lamp groups, including turn signals, fog lights, and brake lights;

[0033] A status processing unit for receiving and processing motor status information from the local one-way SIF data line;

[0034] A signal forwarding unit for forwarding the motor status information to the main bus;

[0035] A transceiver circuit for realizing data interaction with the main bus.

[0036] Based on the above solution, preferably, the instrument includes:

[0037] An information display unit for displaying system status information received from the main bus, including motor status information, vehicle speed information, and fault information.

[0038] Based on the above solution, preferably, the motor controller includes:

[0039] A power control unit for performing brake power-off or acceleration control according to control instructions on the main bus;

[0040] A status monitoring unit for monitoring the operating status, fault status, and speed information of the motor;

[0041] A communication unit for sending motor status information to the rear control box through the local unidirectional SIF data line.

[0042] Based on the above solution, preferably, the communication process of the composite bus includes a sending state, a receiving state, and a release state; in the sending state, the cross-current source circuit drives the bus, and the output is protected by a 15V voltage limit; in the receiving state, signals are received through a low-impedance circuit and interference is filtered; in the release state, the bus is automatically released after sending is completed, waiting for other nodes to respond.

[0043] Based on the above solution, preferably, the system completes a full data interaction within 10 milliseconds; the system has a hardware protection mechanism that automatically cuts off relevant circuits when short circuit or leakage is detected, automatically enters the protection state when the power supply voltage exceeds the system allowable range, and the system automatically resumes normal operation after the fault is eliminated.

[0044] The present invention has the following beneficial effects compared with the prior art:

[0045] (1) By adopting a composite bus architecture (main bus + local SIF data line), the present invention simplifies more than 20 traditional wire harnesses into 5 main connecting wires (1 main bus, 4 power ground wires), reducing the wire harness usage by more than 70%, significantly reducing the vehicle weight and assembly complexity. At the same time, modular design is adopted, improving the scalability and maintenance convenience of the system;

[0046] (2) The transceiver circuit of the present invention adopts a design scheme combining a cross-current source circuit and a voltage limiting circuit. The output current is limited by the cross-current source, the voltage is limited by a diode, and combined with a low-impedance input stage design, effectively improving the reliability and anti-interference ability of signal transmission, enabling the system to still maintain stable operation in a harsh electromagnetic environment;

[0047] (3) The present invention designs a perfect hardware protection mechanism. Through the cooperation of a high-voltage protection circuit and an overcurrent protection circuit, the system can withstand a voltage impact of 100V for 60s, and automatically cuts off relevant circuits when short circuit or leakage is detected, realizing the self-protection function of the system and improving the safety and reliability of the vehicle electrical system;

[0048] (4) The present invention changes the control method of the hazard warning lamp. By quickly toggling the turn signal lamp, the control of the hazard warning lamp is realized, replacing the traditional independent button control method, simplifying the operation, improving the user experience, and reducing the hardware cost of the independent button at the same time;

[0049] (5) The present invention adopts a modular system architecture. Through the rear control box, functions such as load control, status processing, and signal forwarding are realized. Cooperating with the display and fault diagnosis functions of the instrument, a complete status monitoring and fault diagnosis system is constructed, improving the maintainability of the system and the efficiency of fault handling. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0051] Figure 1 is a schematic diagram of the system module structure of the present invention;

[0052] Figure 2 is a schematic diagram of the system architecture of the present invention;

[0053] Figure 3 is a schematic diagram of the transceiver circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0055] As Figure 1 shown, the present invention provides a motor vehicle digital base system based on a composite bus, including:

[0056] The composite bus includes a main bus and a local unidirectional SIF data line. Among them: the main bus adopts a quasi-duplex communication method, and realizes bidirectional data transmission through a single signal line. The signal line adopts a high-level anti-polarity UART communication format; the local unidirectional SIF data line is used to transmit the status information of the motor controller to the rear control box;

[0057] The control module group includes an input device, a front control box, a rear control box, an instrument, and a motor controller. Among them:

[0058] The input device includes a left combined switch and a right combined switch, which are used to implement P - gear control and other input control functions;

[0059] The front control box is electrically connected to the input device, and is used to receive and process control signals, and send control instructions through the main bus;

[0060] The rear control box is connected to the front control box through the main bus, and is used to control the rear load, receive the motor status information transmitted by the local unidirectional SIF data line, and forward it to the main bus;

[0061] The instrument is electrically connected to the main bus through a power line, a ground line and a signal line, and is used to display system status information;

[0062] The motor controller is used to read the control instructions on the main bus and execute corresponding power output control, and at the same time send the status information of the motor to the rear control box through the local unidirectional SIF data line;

[0063] Transceiver circuits are provided at the main bus interfaces of the front control box and the rear control box for signal transmission and reception. The transceiver circuit includes a transmission unit, a reception unit and a protection unit.

[0064] Please refer to Figure 2 , the technical idea of the present invention is as follows: Reconstruct the traditional motor vehicle control system through an innovative composite bus architecture (main bus + local unidirectional SIF data line). The main bus uses a quasi - duplex communication method to achieve two - way data transmission between system modules, while the local unidirectional SIF data line is specifically used for the motor controller to transmit status information to the rear control box, and the rear control box then forwards this information to the main bus. This hierarchical design not only ensures the real - time performance and reliability of the system, but also significantly simplifies the wiring harness structure (reduced from more than 20 traditional ones to 5). At the same time, through special transceiver circuit design (including constant - current source current limiting, 15V voltage limiting protection, etc.) and multiple protection mechanisms (can withstand 100V / 60s voltage impact), the stable operation of the system under harsh working conditions is ensured. This technical route not only reduces the system cost, improves the reliability, but also enhances the maintainability and expandability of the system through modular design, providing a high - cost - performance digital solution for small vehicles such as two - wheelers and three - wheelers.

[0065] It should be noted that the wiring harness structure described in the present invention is 5, which refers to 1 main bus, and the other 4 are power lines and ground lines used to provide energy power. The present invention refers to the main bus connecting the front and rear parts of the motor vehicle and the local unidirectional SIF data line as a composite bus.

[0066] Specifically, in an embodiment of the present invention, the motor vehicle digital base system based on a composite bus adopts a modular design and mainly consists of functional modules such as an input device, a front control box, a rear control box, an instrument, and a motor controller. Among them, the input device, the front control box, and the instrument are located at the front of the motor vehicle, while the rear control box and the motor controller are located at the rear of the motor vehicle. The system electrically connects the front control box and the rear control box through a main bus for bidirectional data transmission.

[0067] The composite bus of the present invention consists of a main bus and a local unidirectional SIF data line. Among them, the main bus adopts a quasi-duplex communication method to achieve bidirectional data transmission through a single signal line, and the signal line adopts a high-level anti-polarity UART communication format; the local unidirectional SIF data line is used for the motor controller to transmit status information to the rear control box. Special transceiver circuits, including a sending unit, a receiving unit, and a protection unit, are provided at the main bus interfaces of the front control box and the rear control box. This design not only simplifies the system wiring but also provides excellent anti-interference ability and a reliable hardware protection mechanism through special circuit design. The bus impedance of the system is relatively low, enabling effective signal transmission within a range of 10 meters, and it has the ability to withstand a voltage impact of 100V / 60s.

[0068] In terms of module connection, the front control box is directly electrically connected to the input device through a wire, used to receive and process the turn signal control signal, and send the processed signal to the main bus through the transceiver circuit. The rear control box, as the core control unit of the system, on the one hand, receives and processes the control signal from the front control box through the composite bus, and on the other hand, is connected to the motor controller through the local unidirectional SIF data line to achieve motor status monitoring and control. The instrument is connected to the composite bus using a three-wire system (power line, ground line, signal line) and is responsible for displaying vehicle status information. This connection method significantly reduces the amount of system wiring harnesses and improves the vehicle assembly efficiency.

[0069] In an embodiment of the present invention, the control method of the hazard warning light is designed. Instead of using the traditional independent button control, it is achieved by quickly toggling the turn signals. When the driver quickly toggles the left turn signal and the right turn signal, the system will recognize this operation and trigger the hazard warning light function, thus simplifying the hardware design, reducing the use of independent buttons, and improving the operation convenience. In addition, the function of the P gear button has also been optimized and designed to endow it with multiple operation modes: single click is used to release the parking lock or end the parking function; double click continuously can turn on the child lock function; long press is used to trigger the inductive unlocking function. This design realizes multiple functions through one button, not only improving the function integration degree of the system but also optimizing the user operation experience.

[0070] The working process design of the system fully considers the requirements of real-time performance and reliability. When the driver operates the turn signal or P gear control through the combination switch, the input signal is first collected and processed by the front control box, and after generating a control instruction, it is sent to the rear control box through the main bus. After receiving the instruction, the rear control box controls the corresponding load (such as the turn signal or brake light). At the same time, the rear control box also receives the status information from the motor controller through the local unidirectional SIF data line and forwards this information to the main bus for the instrument display or other modules to use. In addition, the motor controller adjusts the power output according to the acceleration or brake instruction received from the main bus.

[0071] For high-speed response signals (such as brake information transmission), the system design ensures that the entire data interaction process is completed within 10 milliseconds, that is, from the signal acquisition of the input device to the action execution of the target module is completed within 10 milliseconds. During this process, the transceiver circuits of each module work together in three states: sending, receiving, and releasing to ensure the accuracy and reliability of data transmission. The rear control box also enhances the protection performance of the system under harsh working conditions through high-voltage protection mechanisms and overcurrent protection mechanisms.

[0072] When the system detects an abnormal situation, such as a short circuit, leakage, or the power supply voltage exceeding the allowable range, the protection mechanism will be immediately triggered to cut off the relevant circuit or make the system enter the protection state. After the fault is eliminated, the system can automatically resume normal operation. This multi-level protection mechanism, combined with the system's fault diagnosis function, not only improves the safety of the whole vehicle but also facilitates later maintenance and fault troubleshooting.

[0073] As Figure 3 shown, in an embodiment of the present invention, the transceiver circuit uses a single signal line to achieve bidirectional data transmission and has a perfect protection mechanism at the same time. The transceiver circuit mainly consists of three functional parts: a sending unit, a receiving unit, and a protection unit, and realizes highly reliable signal transmission through a clever circuit design.

[0074] In the design of the sending unit, a scheme combining a constant current source circuit and a voltage limiting circuit is adopted. The constant current source circuit is composed of transistor Q9 and its bias resistors R02 (3.3 kΩ) and R70 (22 kΩ). By precisely controlling the operating point of the transistor, the output current is limited within a safe range. The voltage limiting circuit uses diode DW15V to clamp the output voltage within 15V. This design not only ensures the transmission intensity of the signal but also avoids damage to the system caused by excessive voltage. The input resistor R76 (10 kΩ) is used to receive the control signal, and its accuracy requirement is 0.402% to ensure the accuracy of signal transmission.

[0075] The receiving unit adopts a low-impedance design and is mainly composed of transistor Q62 and related circuit components. The input stage is configured with a common-emitter amplifier circuit, and a suitable bias voltage is provided through resistor R67 (10 kΩ). To improve the anti-interference ability of the system, a filter capacitor C60 (102 / 0402) is configured on the signal path, which can effectively filter out high-frequency interference signals. This low-impedance design not only improves the signal receiving sensitivity but also enhances the working stability of the system in a harsh electromagnetic environment.

[0076] The protection unit is a key part to ensure the reliability of the system. The high-voltage protection circuit consists of diode DT1 (DW3V3) and resistors RT4 (10 kΩ), RT3 (330 Ω), and can withstand a voltage impact of 100 V. Overcurrent protection is achieved by transistor QT2 (2SA5401) in cooperation with diode DT4 (A7). When an abnormal current is detected, the protection circuit will immediately act to cut off the signal transmission path and prevent circuit damage. This multi-level protection mechanism ensures the safety of the system under various abnormal conditions.

[0077] During the working process, the transceiver circuit realizes two-way communication by switching among three states. In the transmitting state, a constant-current source drives the bus to output signals; in the receiving state, a low-impedance circuit cooperates with a filter network to receive and process signals; in the release state, the circuit automatically releases the bus and waits for other nodes to respond. This quasi-duplex communication method not only ensures the reliability of signal transmission but also avoids signal conflicts.

[0078] The entire transceiver circuit is fabricated using surface-mount technology, and key components are all selected as high-precision and high-reliability devices. For example, precision resistors adopt an error grade of 0.402%, and filter capacitors are selected with a 0402 package specification. These carefully selected component parameters, combined with a reasonable circuit layout, enable the system to achieve stable signal transmission within a range of 10 meters and ensure a complete data interaction within 10 milliseconds.

[0079] Specifically, in an embodiment of the present invention, each functional module is organically integrated through a composite bus to form a complete digital base system. The composite bus consists of a main bus and a local unidirectional SIF data line. Among them, the main bus adopts a quasi-duplex communication method to achieve two-way data transmission through a single signal line, and the signal line adopts a high-level anti-polarity UART communication format. The local unidirectional SIF data line is used for the motor controller to transmit status information to the rear control box, and the rear control box then forwards this information to the main bus.

[0080] The system includes modules such as a front control box, a rear control box, an instrument, and a motor controller. These modules cooperate closely through a composite bus, forming an efficient and reliable whole. The front control box receives control signals from input devices (left combination switch and right combination switch), processes them, and sends control instructions through the main bus. The rear control box receives the control instructions from the main bus, controls the rear loads (such as turn signals, fog lights, brake lights), and forwards the motor status information received through the local unidirectional SIF data line to the main bus through a signal forwarding unit. The instrument receives the system status information through the main bus and displays the motor status information, vehicle speed information, and fault information through an information display unit. The motor controller performs power output control according to the control instructions from the main bus and simultaneously sends the motor status information to the rear control box through the local unidirectional SIF data line.

[0081] The system adopts a unified communication protocol and data format, ensuring seamless docking between modules. During the communication process, the transceiver circuits of the main bus work together through the sending state, receiving state, and releasing state: in the sending state, the constant current source circuit drives the bus, and the output is protected by 15V voltage limiting; in the receiving state, signals are received through a low-impedance circuit and interference is filtered; in the releasing state, the bus is automatically released after sending is completed, waiting for other nodes to respond. This design not only ensures the reliability of signal transmission but also avoids signal conflicts.

[0082] The entire system completes a full data interaction within 10 milliseconds, meeting the high-speed response requirements. At the same time, the transceiver circuits set at the interfaces of each module include a high-voltage protection circuit and an overcurrent protection circuit, which can withstand a voltage impact of 100V / 60s and automatically cut off the relevant circuits when short circuit or leakage is detected. The system can automatically resume normal working state after the fault is eliminated. This design significantly improves the reliability and safety of the system.

[0083] The system characteristics of the present invention are mainly reflected in aspects such as the communication process, data interaction timing, protection mechanism, and fault handling. Through the organic combination of these characteristics, high-reliability and real-time system control are achieved.

[0084] In terms of the communication process, the system adopts a three-state switching method to achieve quasi-duplex communication. In the sending state, the constant current source circuit drives the bus to output signals, and the output voltage is protected by 15V voltage limiting, ensuring the signal strength while preventing overvoltage damage. In the receiving state, the system receives signals through a low-impedance circuit and uses filter capacitors to filter out interference, improving the reliability of the signals. In the releasing state, the sending unit automatically releases the bus after completing data transmission, waiting for other nodes to respond. This design avoids signal conflicts and improves communication efficiency.

[0085] The data interaction of the system has significant real-time characteristics. Through optimized communication protocols and efficient signal processing mechanisms, the system can complete a complete data interaction within 10 milliseconds. For control signals that require a quick response, such as brake signals, the system ensures that they can be transmitted from the brake switch to the motor controller within 10 milliseconds and immediately cut off the motor power output. This efficient data interaction mechanism is of great significance to ensuring driving safety.

[0086] In terms of protection mechanism, the system achieves all-round safety protection through three levels of hardware protection circuits. The first level is the high-voltage protection circuit, which consists of diode DT1 and resistor RT4. When the system is subjected to voltage shock, diode DT1 enters the reverse breakdown state and forms a voltage divider circuit with resistor RT4 to clamp the excessive voltage within a safe range. This design ensures that the system will not damage the interface circuit even if it is subjected to a 100V voltage shock for 3 seconds, which far exceeds the 28V withstand voltage of the traditional CAN and RS485 bus. The second level is the overcurrent protection circuit, which is mainly implemented by the cross-current source circuit. The circuit consists of transistor Q9 and its bias resistors R02 (3.3kΩ) and R70 (22kΩ). By accurately setting the operating point of transistor Q9, it automatically enters the saturation zone in the case of overcurrent, thereby limiting the output current. At the same time, the voltage limiting circuit uses diode DW15V to limit the output voltage to less than 15V, forming double protection. When an overcurrent state is detected, the cross-current source circuit immediately reduces the output current to protect the subsequent circuit from damage. The third layer is the anti-interference protection circuit, which adopts a combination of low impedance design and filtering circuit. The input stage circuit uses transistor Q62 with bias resistor to achieve low impedance characteristics, and filters the input signal through filter capacitor C60 to effectively suppress electromagnetic interference. Pull-up resistor R67 provides a stable signal reference level, further improving the system's anti-interference ability.

[0087] In terms of the fault handling process, the system adopts a real-time monitoring and quick response mechanism. First, the system continuously monitors key parameters through a dedicated detection circuit: Short-circuit detection: Determine by detecting whether the bus voltage suddenly drops to nearly 0V; Leakage detection: Monitor whether the leakage current of the system to the ground exceeds the safety threshold; Power supply voltage detection: Compare the power supply voltage of the system with the preset safety range in real time. When an abnormality is detected, the system processes it according to the following process: Fault identification: The system first quickly identifies the fault type. Protection trigger: Activate the corresponding protection mechanism according to the fault type; Short-circuit protection: Immediately cut off the power supply of the relevant load; Leakage protection: Disconnect the leakage circuit to prevent the leakage current; Overvoltage protection: Start the voltage-limiting circuit to clamp the system voltage. State maintenance: The system enters the protection state and sends fault information to the instrument through the communication unit. Automatic recovery: The system continuously monitors the fault state and starts the recovery process when the following conditions are detected: Short-circuit fault elimination: The bus voltage returns to normal; Leakage fault elimination: The leakage current to the ground drops below the safety value; Power supply voltage returns to the normal range. Recovery process: Re-detect the system parameters to confirm that the fault has been eliminated; Gradually restore the power supply of each functional module; Re-initialize the communication bus; Resume normal data interaction.

[0088] This multi-level protection mechanism and perfect fault handling process ensure that the system can quickly respond and automatically recover under various abnormal conditions, effectively preventing safety accidents caused by electrical faults.

[0089] The present invention has a distributed architecture, which is more convenient for system maintenance and fault diagnosis. A handheld fault diagnostic instrument can be equipped or the display instrument of the system can be directly used to intuitively view the vehicle status and fault information, making the fault troubleshooting and repair work more efficient; It can also perform a complete production test during the production link of the vehicle. The cost is reduced.

[0090] In summary, the present invention proposes a motor vehicle digital base system based on a composite bus. Aiming at the problems of the complex and difficult-to-maintain traditional point-to-point wiring harness system and the high cost of the standard bus system, it adopts a quasi-duplex communication method to realize bidirectional data transmission through a single signal line. The system adopts an anti-polarity UART communication format, is equipped with an innovative transceiver circuit design, has excellent anti-interference ability and a reliable hardware protection mechanism, and can withstand a voltage impact of 100V / 30s. Through modular design and a three-wire instrument connection method, the wire harness usage is significantly reduced by 70%, reducing the overall cost. The system also realizes practical functions such as hazard warning light control and P-gear button multi-functional control, and can complete data interaction within 10 milliseconds, ensuring the real-time nature of control. This design not only solves the problems of the wire harness system of small vehicles such as two-wheelers and three-wheelers, but also has significant advantages in terms of reliability, cost, and maintenance convenience, and has broad market application prospects.

[0091] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A digital base system for a motor vehicle based on a composite bus, characterized in that: include: A composite bus, comprising a main bus and a local unidirectional SIF data line, wherein: the main bus adopts a quasi-duplex communication mode, realizes bidirectional data transmission through a single signal line, and the signal line adopts a high-level reverse polarity UART communication format; the local unidirectional SIF data line is used to transmit the status information of the motor controller to the rear control box; The control module group includes an input device, a front control box, a rear control box, an instrument and a motor controller, wherein: The input device includes a left combination switch and a right combination switch for realizing P gear control and other input control functions; The front control box is electrically connected to the input device, and is used to receive and process control signals, and send control instructions through the main bus; The rear control box is connected to the front control box via the main bus, and is used to control the rear load, and receive the motor status information transmitted by the local unidirectional SIF data line, and forward it to the main bus; The instrument is electrically connected to the main bus via a power line, a ground line and a signal line, and is used to display system status information; The motor controller is used to read the control instructions on the main bus and execute the corresponding power output control, and at the same time send the motor status information to the rear control box through the local unidirectional SIF data line; The main bus interfaces of the front control box and the rear control box are both provided with a transceiver circuit for sending and receiving signals. The transceiver circuit includes a sending unit, a receiving unit and a protection unit.

2. A composite bus-based digital base system for motor vehicles as claimed in claim 1, characterized in that: The transmitting unit of the transceiver circuit includes a horizontal current source circuit and a voltage limiting circuit: The cross-current source circuit is composed of a transistor Q9 and its bias resistor, and is used to limit the output current; The voltage limiting circuit is composed of a diode DW15V, which is used to limit the output voltage to within fifteen volts; The sending unit further includes an input resistor R76 and bias resistors R02 and R70, wherein the input resistor R76 is used to receive a control signal, and the bias resistors R02 and R70 are used to set a cross-current source operating point.

3. A composite bus-based digital base system for motor vehicles as claimed in claim 2, characterized in that: The receiving unit of the transceiver circuit includes an input stage circuit and a filter circuit: The input stage circuit is composed of transistor Q62 and its bias resistor, and adopts a low impedance design; The filter circuit is composed of a capacitor C60, which is used to filter out interference signals; The receiving unit further includes a pull-up resistor R67 for providing a signal reference level.

4. A composite bus-based digital base system for motor vehicles as claimed in claim 3, characterized in that: The protection unit of the transceiver circuit includes a high voltage protection circuit and an overcurrent protection circuit: The high voltage protection circuit is composed of a diode DT1 and a resistor RT4, and can withstand a voltage of one hundred volts; The overcurrent protection circuit realizes current limitation through the cross-current source circuit; The protection unit also includes an anti-interference circuit, which is implemented through a low impedance design and a filter capacitor.

5. A composite bus-based digital base system for motor vehicles as claimed in claim 1, characterized in that: The left combination switch and the right combination switch in the input device are configured with a P gear control function; the front control box includes: a turn signal control unit, used for processing a turn signal control signal from the input device; The transceiver circuit is used to send the processed control signal to other modules through the main bus.

6. A composite bus-based digital base system for motor vehicles as claimed in claim 1, characterized in that: The rear control box comprises: Load control unit, used to control the light group, including turn signal, fog light, brake light; A state processing unit, used for receiving and processing the motor state information from the local unidirectional SIF data line; A signal forwarding unit, used for forwarding the motor status information to the main bus; The transceiver circuit is used to realize data interaction with the main bus.

7. A composite bus-based digital base system for motor vehicles as claimed in claim 1, characterized in that: The instrument comprises: The information display unit is used to display the system status information received from the main bus, including motor status information, vehicle speed information and fault information.

8. The composite bus-based digital base system for automobiles as claimed in claim 1, characterized in that: The motor controller comprises: A power control unit, used to execute brake power-off or acceleration control according to the control instructions on the main bus; A status monitoring unit is used to monitor the running status, fault status and speed information of the motor; The communication unit is used to send the motor status information to the rear control box through the local unidirectional SIF data line.

9. A composite bus-based digital base system for motor vehicles as claimed in claim 1, characterized in that: The communication process of the composite bus includes a sending state, a receiving state and a releasing state; in the sending state, the cross-current source circuit drives the bus, and the output is protected by a 15-volt voltage limit; in the receiving state, the signal is received through a low-impedance circuit and interference is filtered out; in the releasing state, the bus is automatically released after the sending is completed, waiting for responses from other nodes.

10. The composite bus-based digital base system for automobiles according to claim 1, characterized in that: The system completes a complete data interaction within ten milliseconds; the system has a hardware protection mechanism, which automatically cuts off the relevant circuit when a short circuit or leakage is detected, and automatically enters a protection state when the power supply voltage exceeds the system's allowable range. After the fault is eliminated, the system automatically returns to a normal working state.

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