Motor vehicle digital base system based on a composite bus

Abstract

The application provides a motor vehicle digital base system based on a composite bus, and relates to the technical field of motor vehicle control technology.The motor vehicle digital base system comprises a composite bus, wherein the composite bus comprises a main bus and a local one-way SIF data line; the main bus adopts a quasi-duplex communication mode, realizes bidirectional data transmission through a single signal line, and adopts a higher-level reverse-polarity UART communication format; and the local one-way SIF data line is used for transmitting state information of a motor controller to a rear control box; the control module group comprises an input device, a front control box, a rear control box, an instrument and a motor controller; and the main bus interfaces of the front control box and the rear control box are both provided with a transceiver circuit, which comprises a sending unit, a receiving unit and a protection unit.The motor vehicle digital base system can solve the technical problems of a large number of wire harnesses, high manufacturing cost, low voltage resistance, difficult maintenance, high system cost and poor expansibility in the prior art, realizes a high-performance-price-ratio system integration scheme, and ensures the real-time performance of signal transmission and the robustness of system operation.

Description

Technical Field

[0001] This invention relates to the field of motor vehicle control technology, and in particular to a motor vehicle digital base system based on a composite bus. Background Technology

[0002] In the field of automotive wiring harness systems, the traditional single-wire direct-connection point-to-point system wiring harness is the most basic technical solution. This method directly controls loads such as lights or moving parts through switches, and status information is transmitted to the indicator instruments one-to-one via signal lines. This solution requires more than 20 wiring harnesses to connect the front and rear of the vehicle, which not only increases the overall vehicle weight and cost, but also leads to complex assembly, difficult maintenance, and significant shortcomings in system scalability and integration.

[0003] With the development of automotive electronics technology, standard distributed bus systems (such as CAN and RS485) have gradually become widely used. While these bus systems offer advantages such as high data transmission rates and flexible networking, their voltage withstand capabilities are generally low. For example, non-isolated CAN and RS485 buses are only suitable for systems below 28V. However, in small vehicle systems such as two-wheeled and three-wheeled vehicles, the need for complex system isolation and protection circuits to improve voltage withstand capabilities leads to high hardware costs and makes it difficult to guarantee system reliability.

[0004] Currently, mainstream gasoline-powered motorcycles and electric two-wheelers and three-wheelers on the market still widely use the traditional single-wire direct-connection point-to-point system wiring harness. This technical solution not only suffers from a large number of wiring harnesses (more than 20) and complex layout, but also has significant shortcomings in terms of functional expansion, system integration, and fault diagnosis. Furthermore, existing technologies struggle to meet the growing market demands in terms of voltage withstand capability (generally below 28V), system reliability, and cost-effectiveness. Therefore, there is an urgent need to develop an on-board wiring harness bus connection technology that combines reliability and cost advantages. Summary of the Invention

[0005] In view of this, the present invention proposes a digital chassis system for motor vehicles based on a composite bus. This system aims to solve the technical problems of existing technologies, such as a large number of wiring harnesses and complex connections, high manufacturing costs, low withstand voltage, difficult maintenance, high system costs and poor scalability. Through composite bus architecture design and reliable transceiver circuit protection mechanism, a cost-effective system integration solution is achieved, while ensuring the real-time performance of signal transmission and the reliability and robustness of system operation, so as to meet the actual application needs of small vehicles such as two-wheeled vehicles and three-wheeled vehicles.

[0006] The technical solution of this invention is implemented as follows:

[0007] This invention provides a vehicle digital chassis system based on a composite bus, comprising:

[0008] The composite bus includes a main bus and local unidirectional SIF data lines, wherein: the main bus adopts a quasi-duplex communication mode, realizing 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 lines are used to transmit the status information of the motor controller to the rear control box.

[0009] The control module group includes input devices, a front control box, a rear control box, instruments, and a motor controller, wherein:

[0010] The input device includes a left combination switch and a right combination switch, used to realize 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 commands through the main bus.

[0012] 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.

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

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

[0015] Both the front control box and the rear control box are equipped with transceiver circuits at their main bus interfaces for transmitting and receiving signals. The transceiver circuits include a transmitting unit, a receiving unit, and a protection unit.

[0016] Based on the above scheme, preferably, the transmitting unit of the transceiver circuit includes a current source circuit and a voltage limiting circuit:

[0017] The current source circuit consists of transistor Q9 and its bias resistor, 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 to within 15 volts.

[0019] The transmitting unit further includes an input resistor R76 and bias resistors R02 and R70, wherein 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 current source.

[0020] Based on the above scheme, 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 bias resistor, and adopts a low impedance design.

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

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

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

[0025] The high-voltage protection circuit consists of diode DT1 and resistor RT4, and can withstand 100 volts.

[0026] The overcurrent protection circuit achieves current limiting through the cross-current source circuit;

[0027] The protection unit also includes an anti-interference circuit, which is implemented through low impedance design and filter capacitors.

[0028] Based on the above scheme, preferably, the left and right combination switches in the input device are equipped with a P-position control function; the front control box includes:

[0029] A turn signal control unit is used to process turn signal control signals from the input device;

[0030] The transceiver circuit is used to send the processed control signals to other modules via the main bus.

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

[0032] The load control unit is used to control the lighting system, including turn signals, fog lights, and brake lights.

[0033] A status processing unit is used to receive and process motor status information from the local unidirectional SIF data line;

[0034] A signal forwarding unit is used to forward the motor status information to the main bus;

[0035] The transceiver circuit is used to enable data interaction with the main bus.

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

[0037] The information display unit is used to display 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] The power control unit is used to execute brake power cut-off or acceleration control according to the control commands on the main bus;

[0040] The status monitoring unit is used to monitor the motor's operating status, fault status, and speed information;

[0041] The communication unit is used to send motor status information to the rear control box via the local unidirectional SIF data line.

[0042] Based on the above scheme, preferably, the communication process of the composite bus includes a sending state, a receiving state, and a releasing state; in the sending state, the 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, and the bus waits for the response of other nodes.

[0043] Based on the above scheme, preferably, the system completes a complete data interaction within ten milliseconds; the system has a hardware protection mechanism that automatically cuts off the relevant circuit when a short circuit or leakage is detected, automatically enters the protection state when the power supply voltage exceeds the system's allowable range, and automatically returns to normal operation after the fault is cleared.

[0044] The present invention has the following advantages over the prior art:

[0045] (1) This invention simplifies the traditional 20+ wire harnesses to 5 main connection lines (1 main bus and 4 power ground lines) by adopting a composite bus architecture (main bus + local SIF data line), reducing the number of wire harnesses by more than 70%, which significantly reduces the overall vehicle weight and assembly complexity. At the same time, the modular design improves the system's scalability and maintenance convenience;

[0046] (2) The transceiver circuit of the present invention adopts a design scheme combining a current source circuit and a voltage limiting circuit. The current source limits the output current, and the diode is used to limit the voltage. Combined with the low impedance input stage design, the reliability of signal transmission and anti-interference ability are effectively improved, so that the system can still maintain stable operation in harsh electromagnetic environments.

[0047] (3) The present invention has designed a complete hardware protection mechanism. Through the cooperation of high voltage protection circuit and overcurrent protection circuit, the system can withstand a voltage surge of 100V for 60s. When a short circuit or leakage is detected, the relevant circuit is automatically cut off, realizing the self-protection function of the system and improving the safety and reliability of the vehicle electrical system.

[0048] (4) This invention changes the control method of the hazard warning light. The hazard warning light is controlled by quickly toggling the turn signal, which replaces the traditional independent button control method, simplifies the operation, improves the user experience, and reduces the hardware cost of the independent button.

[0049] (5) The present invention adopts a modular system architecture, realizes the functions of load control, status processing and signal forwarding through the rear control box, and, together with the display and fault diagnosis functions of the instrument, constructs a complete status monitoring and fault diagnosis system, which improves the maintainability and fault handling efficiency of the system. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

[0053] Figure 3 This is a schematic diagram of the transceiver circuit of the present invention. Detailed Implementation

[0054] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not 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 effort are within the scope of protection of the present invention.

[0055] like Figure 1 As shown, the present invention provides a vehicle digital docking station system based on a composite bus, comprising:

[0056] The composite bus includes a main bus and local unidirectional SIF data lines, wherein: the main bus adopts a quasi-duplex communication mode, realizing 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 lines are used to transmit the status information of the motor controller to the rear control box.

[0057] The control module group includes input devices, a front control box, a rear control box, instruments, and a motor controller, wherein:

[0058] The input device includes a left combination switch and a right combination switch, used to realize 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 commands through the main bus.

[0060] 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.

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

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

[0063] Both the front control box and the rear control box are equipped with transceiver circuits at their main bus interfaces for transmitting and receiving signals. The transceiver circuits include a transmitting unit, a receiving unit, and a protection unit.

[0064] Please see Figure 2 The technical approach of this invention is as follows: A novel composite bus architecture (main bus + local unidirectional SIF data line) is used to reconstruct the traditional vehicle control system. The main bus employs quasi-duplex communication to achieve bidirectional 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, which then forwards this information to the main bus. This layered design ensures both the real-time performance and reliability of the system, while significantly simplifying the wiring harness structure (reducing it from over 20 wires to 5). Simultaneously, through special transceiver circuit design (including cross-current source current limiting and 15V voltage limiting protection) and multiple protection mechanisms (capable of withstanding 100V / 60s voltage surges), stable system operation under harsh conditions is ensured. This technical approach not only reduces system costs and improves reliability but also enhances system maintainability and scalability through modular design, providing a cost-effective digital solution for small vehicles such as two-wheeled and three-wheeled vehicles.

[0065] It should be noted that the wiring harness structure described in this invention consists of 5 wires, referring to 1 main bus and 4 power and ground wires used to provide energy. This invention refers to the main bus that connects the front and rear of the vehicle and the local unidirectional SIF data line as a composite bus.

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

[0067] The composite bus of this invention consists of a main bus and local unidirectional SIF data lines. The main bus adopts a quasi-duplex communication mode, realizing 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 lines are used by the motor controller to transmit status information to the rear control box. Dedicated transceiver circuits are set at the main bus interface of the front and rear control boxes, including a transmitting unit, a receiving unit, and a protection unit. This design not only simplifies system wiring but also provides excellent anti-interference capability and a reliable hardware protection mechanism through special circuit design. The system has low bus impedance, can achieve effective signal transmission within a 10-meter range, and is capable of withstanding a 100V / 60s voltage surge.

[0068] In terms of module connectivity, the front control box is directly electrically connected to the input devices via wires to receive and process turn signal control signals, and then transmits the processed signals to the main bus via transceiver circuits. The rear control box, as the core control unit of the system, receives and processes control signals from the front control box via a composite bus, and connects to the motor controller via a local unidirectional SIF data line to achieve motor status monitoring and control. The instrument cluster uses a three-wire system (power line, ground line, signal line) to connect to the composite bus and is responsible for displaying vehicle status information. This connection method significantly reduces the amount of wiring harness used in the system and improves the overall vehicle assembly efficiency.

[0069] In one embodiment of the invention, the control method for the hazard warning lights has been redesigned. Instead of using traditional independent buttons, it is controlled by quickly flicking the turn signals. When the driver quickly flicks the left and right turn signals, the system recognizes the operation and triggers the hazard warning lights, thus simplifying the hardware design, reducing the use of independent buttons, and improving operational convenience. Furthermore, the P-gear button has also been optimized, offering multiple operating modes: a single press releases the parking lock or ends the parking function; two consecutive presses activate the child lock; and a long press triggers the sensor-activated unlock function. This design achieves multiple functions with a single button, improving both the system's functional integration and the user experience.

[0070] The system's workflow design fully considers real-time and reliability requirements. When the driver operates the turn signal or P gear control via the combination switch, the input signal is first collected and processed by the front control box, generating a control command which is then sent to the rear control box via the main bus. Upon receiving the command, the rear control box controls the corresponding load (e.g., turn signal or brake light). Simultaneously, the rear control box also receives status information from the motor controller via a local unidirectional SIF data line and forwards this information to the main bus for use by the instrument display or other modules. Furthermore, the motor controller adjusts the power output based on acceleration or braking commands received from the main bus.

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

[0072] When the system detects an abnormality, such as a short circuit, leakage, or power supply voltage exceeding the allowable range, the protection mechanism will be triggered immediately, cutting off the relevant circuits or putting the system into a protection state. After the fault is cleared, the system can automatically resume normal operation. This multi-layered protection mechanism, combined with the system's fault diagnosis function, not only improves the overall vehicle safety but also facilitates later maintenance and fault diagnosis.

[0073] like Figure 3 As shown, in one embodiment of the present invention, the transceiver circuit uses a single signal line to achieve bidirectional data transmission, while also possessing a comprehensive protection mechanism. The transceiver circuit mainly consists of three functional parts: a transmitting unit, a receiving unit, and a protection unit. Through ingenious circuit design, highly reliable signal transmission is achieved.

[0074] The design of the transmitting unit employs a combination of a current source circuit and a voltage limiting circuit. The current source circuit consists of transistor Q9 and its bias resistors R02 (3.3kΩ) and R70 (22kΩ). By precisely controlling the transistor's operating point, the output current is limited to a safe range. The voltage limiting circuit uses diode DW15V to clamp the output voltage below 15V. This design ensures signal transmission strength while preventing damage to the system from excessive voltage. The input resistor R76 (10kΩ) is used to receive control signals, with an accuracy requirement of 0.402% to ensure accurate signal transmission.

[0075] The receiving unit employs a low-impedance design, primarily consisting of transistor Q62 and related circuit components. The input stage utilizes a common-emitter amplifier configuration, with a suitable bias voltage provided by resistor R67 (10kΩ). To enhance the system's anti-interference capability, a filter capacitor C60 (102 / 0402) is incorporated into the signal path, effectively filtering out high-frequency interference signals. This low-impedance design not only improves signal reception sensitivity but also enhances the system's operational stability in harsh electromagnetic environments.

[0076] The protection unit is a crucial component ensuring system reliability. The high-voltage protection circuit, composed of diode DT1 (DW3V3) and resistors RT4 (10kΩ) and RT3 (330Ω), can withstand voltage surges of 100V. Overcurrent protection is implemented using transistor QT2 (2SA5401) in conjunction with diode DT4 (A7). When an abnormal current is detected, the protection circuit immediately activates, cutting off the signal transmission path to prevent circuit damage. This multi-layered protection mechanism ensures system safety under various abnormal conditions.

[0077] During operation, the transceiver circuit achieves bidirectional communication by switching between three states. In the transmit state, a current source drives the bus to output a signal; in the receive state, a low-impedance circuit, in conjunction with a filter network, receives and processes the signal; in the release state, the circuit automatically releases the bus and waits for responses from other nodes. This quasi-duplex communication method ensures both the reliability of signal transmission and avoids signal collisions.

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

[0079] Specifically, in one embodiment of the present invention, the functional modules are organically integrated through a composite bus to form a complete digital base system. The composite bus consists of a main bus and local unidirectional SIF data lines. The main bus adopts a quasi-duplex communication mode, realizing 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 lines are used by the motor controller to transmit status information to the rear control box, which then forwards this information to the main bus.

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

[0081] The system employs a unified communication protocol and data format, ensuring seamless integration between modules. During communication, the main bus's transceiver circuits work collaboratively through transmit, receive, and release states: in transmit state, a current source circuit drives the bus, with the output protected by a 15V voltage limit; in receive state, a low-impedance circuit receives signals and filters out interference; in release state, the bus is automatically released after transmission, awaiting responses from other nodes. This design ensures reliable signal transmission while avoiding signal conflicts.

[0082] The entire system completes a full data exchange within 10 milliseconds, meeting the high-speed response requirement. Simultaneously, the transceiver circuits at each module interface include high-voltage protection and overcurrent protection circuits, capable of withstanding 100V / 60s voltage surges. They automatically disconnect relevant circuits upon detecting short circuits or leakage, and the system automatically returns to normal operation after the fault is cleared. This design significantly improves the system's reliability and safety.

[0083] The system characteristics of this invention are mainly reflected in the communication process, data interaction timing, protection mechanism and fault handling. Through the organic combination of these characteristics, a highly reliable and real-time system control is achieved.

[0084] In terms of communication, the system employs a three-state switching method to achieve quasi-duplex communication. In transmit mode, the current source circuit drives the bus output signal, with the output voltage limited by 15V to ensure signal strength while preventing overvoltage damage. In receive mode, the system receives the signal through a low-impedance circuit and uses filter capacitors to filter out interference, improving signal reliability. In release mode, the transmitting unit automatically releases the bus after completing data transmission, waiting for responses from other nodes. This design avoids signal conflicts and improves communication efficiency.

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

[0086] In terms of protection mechanisms, the system achieves comprehensive safety protection through three layers of hardware protection circuits. The first layer is a high-voltage protection circuit, consisting of diode DT1 and resistor RT4. When the system is subjected to a voltage surge, diode DT1 enters a reverse breakdown state, forming a voltage divider circuit with resistor RT4 to clamp the excessive voltage within a safe range. This design ensures that even under a 100V voltage surge for 3 seconds, the interface circuit will not be damaged, far exceeding the 28V withstand voltage capability of traditional CAN and RS485 buses. The second layer is an overcurrent protection circuit, mainly implemented through a current source circuit. This circuit consists of transistor Q9 and its bias resistors R02 (3.3kΩ) and R70 (22kΩ). By precisely setting the operating point of transistor Q9, it automatically enters the saturation region under overcurrent conditions, thereby limiting the output current. At the same time, the voltage limiting circuit uses diode DW15V to limit the output voltage to within 15V, forming dual protection. When an overcurrent condition is detected, the current source circuit immediately reduces the output current, protecting the subsequent circuits from damage. The third layer is the anti-interference protection circuit, which combines a low-impedance design with a filtering circuit. The input stage circuit uses transistor Q62 with a bias resistor to achieve low impedance characteristics, while the input signal is filtered by 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 capability.

[0087] Regarding fault handling procedures, the system employs a real-time monitoring and rapid response mechanism. First, the system continuously monitors key parameters through dedicated detection circuits: Short-circuit detection: This is determined by detecting whether the bus voltage suddenly drops to near 0V; Leakage detection: This monitors whether the system's leakage current to ground exceeds a safe threshold; Power supply voltage detection: This compares the system power supply voltage with a preset safe range in real time. When an anomaly is detected, the system handles it according to the following procedure: Fault identification: The system first quickly identifies the fault type. Protection triggering: Activates the corresponding protection mechanism based on the fault type; Short-circuit protection: Immediately cuts off the power supply to the relevant load; Leakage protection: Disconnects the leakage circuit to prevent leakage current; Overvoltage protection: Activates the voltage limiting circuit to clamp the system voltage. Status maintenance: The system enters a protection state and sends fault information to the instruments via the communication unit. Automatic recovery: The system continuously monitors the fault status and initiates the recovery process when the following conditions are detected: Short-circuit fault elimination: Bus voltage returns to normal; Leakage fault elimination: Leakage current to ground drops below a safe value; Power supply voltage returns to the normal range. Recovery process: Re-detects system parameters to confirm that the fault has indeed been eliminated; Gradually restores power to each functional module; Reinitializes the communication bus; Restores normal data interaction.

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

[0089] This invention features a distributed architecture, which facilitates system maintenance and fault diagnosis. It can be equipped with a handheld diagnostic tool or directly utilize the system's display instruments to intuitively view the vehicle's status and fault information, making troubleshooting and repair more efficient. Furthermore, it allows for complete production testing during the vehicle manufacturing process, thereby reducing costs.

[0090] In summary, this invention proposes a digital chassis system for motor vehicles based on a composite bus. Addressing the challenges of complex and difficult-to-maintain traditional point-to-point wiring harness systems, and the high cost of standard bus systems, it employs a quasi-duplex communication method, achieving bidirectional data transmission through a single signal line. The system uses a reverse polarity UART communication format and features an innovative transceiver circuit design, exhibiting excellent anti-interference capabilities and reliable hardware protection mechanisms, capable of withstanding 100V / 30s voltage surges. Through modular design and a three-wire instrument panel connection, the wiring harness usage is significantly reduced by 70%, lowering the overall cost. The system also implements practical functions such as hazard warning light control and multi-functional control of the P-gear button, completing data interaction within 10 milliseconds to ensure real-time control. This design not only solves the wiring harness system problems of small vehicles such as two-wheeled and three-wheeled vehicles but also offers significant advantages in reliability, cost, and ease of maintenance, demonstrating broad market application prospects.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vehicle digital chassis system based on a composite bus, characterized in that, It includes a composite bus and a control module group. The composite bus includes a main bus and a local unidirectional SIF data line. The control module group includes input devices, a front control box, a rear control box, instruments, and a motor controller. in: The main bus adopts a quasi-duplex communication mode, realizing bidirectional data transmission through a single signal line. The signal line adopts a high-level reverse polarity UART communication format. The local unidirectional SIF data line is used to transmit the motor status information of the motor controller to the rear control box. The input device includes a left combination switch and a right combination switch, used to realize 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 commands 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 control commands on the main bus and execute corresponding power output control, and at the same time send motor status information to the rear control box through the local unidirectional SIF data line. Both the front control box and the rear control box are equipped with transceiver circuits at their main bus interfaces for transmitting and receiving signals. The transceiver circuits include a transmitting unit, a receiving unit, and a protection unit. The transmitting unit of the transceiver circuit includes a constant current source circuit and a voltage limiting circuit: The constant current source circuit consists of transistor Q9 and its bias resistor, and is used to limit the output current; The voltage limiting circuit is composed of a diode DW15V and is used to limit the output voltage to within 15 volts. The transmitting unit further includes an input resistor R76 and bias resistors R02 and R70, wherein 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. The receiving unit of the transceiver circuit includes an input stage circuit and a filtering circuit: The input stage circuit consists of transistor Q62 and its bias resistor, and adopts a low impedance design. The filter circuit consists of capacitor C60 and is used to filter out interference signals. The receiving unit also includes a pull-up resistor R67 for providing a signal reference level; The protection unit of the transceiver circuit includes a high-voltage protection circuit and an overcurrent protection circuit. The high-voltage protection circuit consists of diode DT1 and resistor RT4, and can withstand 100 volts. The overcurrent protection circuit achieves current limiting through the constant current source circuit; The protection unit also includes an anti-interference circuit, which is implemented through low impedance design and filter capacitors.

2. The vehicle digital chassis system based on a composite bus as described in claim 1, characterized in that, The left and right combination switches in the input device are equipped with a P-position control function; the front control box includes: A turn signal control unit is used to process turn signal control signals from the input device; The transceiver circuit is used to send the processed control signals to other modules via the main bus.

3. The vehicle digital chassis system based on a composite bus as described in claim 1, characterized in that, The rear control box includes: The load control unit is used to control the lighting system, including turn signals, fog lights, and brake lights. A status processing unit is used to receive and process motor status information from the local unidirectional SIF data line; A signal forwarding unit is used to forward the motor status information to the main bus; The transceiver circuit is used to enable data interaction with the main bus.

4. The vehicle digital chassis system based on a composite bus as described in claim 1, characterized in that, The instrument includes: The information display unit is used to display system status information received from the main bus, including motor status information, vehicle speed information, and fault information.

5. A vehicle digital chassis system based on a composite bus as described in claim 1, characterized in that, The motor controller includes: The power control unit is used to execute brake power cut-off or acceleration control according to the control commands on the main bus; The status monitoring unit is used to monitor the motor's operating status, fault status, and speed information; The communication unit is used to send motor status information to the rear control box via the local unidirectional SIF data line.

6. The vehicle digital chassis system based on a composite bus as described 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 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 transmission is completed, and the bus waits for responses from other nodes.

7. The vehicle digital chassis system based on a composite bus as described in claim 1, characterized in that, The system completes a full data interaction within ten milliseconds; the system has a hardware protection mechanism that automatically cuts off the relevant circuits when a short circuit or leakage is detected, automatically enters the protection state when the power supply voltage exceeds the system's allowable range, and automatically returns to normal operation after the fault is cleared.

Images