Daisy chain communication diagnostic methods, battery management systems and equipment

Abstract

This invention provides a daisy-chain communication diagnostic method, a battery management system, and a device. The daisy-chain communication diagnostic method is applied to the battery management system and device, diagnosing the communication of the daisy chain based on its operating mode. In the first mode, N front-end units are accessed in real time, starting from the front-end unit connected to the bridging chip. The daisy-chain communication is considered normal only if N front-end units are accessed; otherwise, it is considered faulty. In the second mode, each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain. The heartbeat signal sent by the following front-end unit is monitored within a preset time, and the communication status of the daisy chain is determined based on the monitoring results. This allows for continuous monitoring of the daisy-chain status even during system sleep mode.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a daisy-chain communication diagnostic method, battery management system, and device. Background Technology

[0002] In recent years, daisy chain topology has been widely used in the field of communications. Currently, systems that commonly use daisy chain topology include DDR, battery management systems, and so on.

[0003] Existing daisy-chain topologies often employ a centralized architecture. In the daisy-chain topology of a battery management system (BMS), information collected by each front-end unit is transmitted to the microcontroller through an interface of a bridge chip. In BMS systems using daisy-chaining, communication between individual sampling chips is achieved via a daisy-chain method. However, in practical applications, wiring harness connections and connections between sampling chips are prone to failure. If any sampling chip experiences a communication problem, the MCU will be unable to read information from subsequent chips in the daisy chain.

[0004] Current daisy-chain BMS systems typically monitor the daisy-chain status in real time while the system is in operation. However, this monitoring method is energy-intensive and cannot continuously monitor the connections between the wiring harness and the sampling chips when the system is in sleep mode.

[0005] Therefore, how to continuously monitor the daisy chain status when the system is in sleep mode has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0006] This invention provides a daisy-chain communication diagnostic method, a battery management system, and a device to solve the technical problem of how to continuously monitor the daisy-chain status when the system is in a dormant state.

[0007] According to a first aspect of the present invention, a daisy-chain communication diagnostic method is provided, wherein the daisy chain includes a bridge chip and N front-end units connected in sequence electrically, wherein N is an integer greater than 1;

[0008] The method includes:

[0009] The working mode of the daisy chain is determined, wherein the working mode includes a first mode and a second mode;

[0010] Diagnose the communication of the daisy chain based on its operating mode; among which:

[0011] If the working mode is mode 1, then perform the following steps:

[0012] Real-time access to the N front-end units starts from the front-end unit connected to the bridging chip;

[0013] The communication status of the daisy chain is determined based on the access status. If N front-end units are accessed, the communication of the daisy chain is determined to be in a normal state; otherwise, the communication of the daisy chain is determined to be in a fault state.

[0014] If the working mode is the second mode, then perform the following steps:

[0015] Each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain;

[0016] The heartbeat signal sent by the next front-end unit is monitored within a preset time.

[0017] The communication status of the daisy chain is determined based on the monitoring data. If a heartbeat signal is detected from the next front-end unit, the communication between the front-end unit and the next front-end unit is determined to be normal, and the preset time is reset. Otherwise, the communication between the front-end unit and the next front-end unit is determined to be faulty, and an alarm signal is sent to the bridging chip.

[0018] Optionally, before each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain, the method further includes:

[0019] The access type of the daisy chain is determined, including one-way access and two-way access.

[0020] Optionally, each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain, specifically including:

[0021] If the access type is one-way access, the farthest sampling unit that the bridging chip can access is selected as the top unit of the daisy chain. Starting from the top unit, each front-end unit periodically sends a heartbeat signal to the previous front-end unit.

[0022] If the access type is bidirectional, the (i-1)th front-end unit is selected as the first top unit. Between the first and (i-1)th front-end units in the daisy chain, each front-end unit periodically sends the heartbeat signal to the previous front-end unit. The ith front-end unit is selected as the second top unit. Between the ith and Nth front-end units in the daisy chain, each front-end unit periodically sends the heartbeat signal to the next front-end unit, where i is an integer and 1 < i < N.

[0023] Optionally, after determining the access type of the daisy chain and before each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain, the method further includes:

[0024] Each front-end unit is inspected after a set time.

[0025] The cumulative number of inspections is calculated. When the number of inspections reaches J, a heartbeat signal is sent to the previous front-end unit; where J is a positive integer and J≥1.

[0026] After sending a heartbeat signal to the previous front-end unit, reset the number of inspections.

[0027] Optionally, the time required for J inspections is less than the preset time.

[0028] According to a second aspect of the present invention, a battery management system is provided for implementing the daisy-chain communication diagnostic method provided in any of the first aspects of the present invention, comprising: a main control chip, a bridging chip, a power management chip, N acquisition front-end units and N battery packs, wherein N is an integer greater than 1;

[0029] The first and second terminals of the power management chip are respectively coupled to the first terminal of the main control chip and the first terminal of the bridge chip; the second terminal of the main control chip is coupled to the second terminal of the bridge chip; the third terminal of the bridge chip is coupled to the first acquisition front-end unit; the N acquisition front-end units are electrically connected sequentially, and each acquisition front-end unit is correspondingly coupled to a battery pack, forming the daisy chain; wherein:

[0030] The main control chip is used to access the data of the N acquisition front-end units in real time when the daisy chain is in the first mode;

[0031] Each acquisition front-end unit is configured to: detect the current status parameters of each cell in the corresponding battery pack; detect the current working status of the daisy chain; periodically send a heartbeat signal to the preceding acquisition front-end unit along the communication direction of the daisy chain only when the main control chip is in sleep mode; and monitor the heartbeat signal sent by the following acquisition front-end unit within a preset time range to determine the communication status with the following acquisition front-end unit; and control whether to send an alarm signal to the power management chip through the bridging chip based on the determination result.

[0032] The power management chip is used to wake up the main control chip when it receives the alarm signal.

[0033] Optionally, the acquisition front-end unit is specifically used to: monitor the heartbeat signal sent by the next acquisition front-end unit within a preset time range, so as to determine whether the corresponding acquisition front-end unit has a communication failure;

[0034] If the heartbeat signal is received from the next acquisition front-end unit within the preset time range, the communication with the next acquisition front-end unit is determined to be in a normal state, and the preset time is reset; otherwise, the communication with the next acquisition front-end unit is determined to be in a fault state, and an alarm signal is sent to the bridging chip.

[0035] Optionally, the fourth terminal of the bridging chip is coupled to the Nth acquisition front-end unit.

[0036] Optionally, the main control chip is further configured to select the (i-1)th acquisition front-end unit as the first top unit and the i-th acquisition front-end unit as the second top unit, where i is an integer and 1 < i < N.

[0037] Optionally, the acquisition front-end unit is further configured to: periodically send the heartbeat signal to the previous acquisition front-end unit between the first acquisition front-end unit and the (i-1)th acquisition front-end unit in the daisy chain; and periodically send the heartbeat signal to the next acquisition front-end unit between the i-th acquisition front-end unit and the N-th acquisition front-end unit in the daisy chain.

[0038] Optionally, the main control chip is also used to view the error information in the alarm signal when it is woken up.

[0039] Optionally, the bridging chip is also used to convert the data pulse signal sent by the main control chip into a corresponding isolated communication data encoding signal.

[0040] According to a third aspect of the present invention, an apparatus is provided, comprising a battery management system provided in any of the second aspects of the present invention.

[0041] In the daisy-chain communication diagnostic method provided by this invention, the communication of the daisy chain is diagnosed by determining the working mode of the daisy chain. If the working mode is the first mode, N front-end units are accessed in real time starting from the front-end unit connected to the bridging chip. The communication of the daisy chain is judged to be in a normal state only if the number of accessed front-end units is N; otherwise, it is in a fault state. If the working mode is the second mode, each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain. The heartbeat signal sent by the following front-end unit is monitored within a preset time. Only when the heartbeat signal sent by the following front-end unit is detected is the communication between the front-end unit and the following front-end unit judged to be in a normal state, and the preset time is reset; otherwise, it is judged to be in a fault state, and an alarm signal is sent to the bridging chip, thereby enabling continuous monitoring of the daisy chain status when the system is in sleep mode.

[0042] The battery management system and device provided by this invention employ the aforementioned daisy-chain communication diagnostic method. A power management chip is coupled to both a main control chip and a bridge chip, with the main control chip coupled to the bridge chip. The bridge chip is coupled to the first acquisition front-end unit, and N acquisition front-end units are sequentially electrically connected. Each acquisition front-end unit is coupled to a battery pack, forming a daisy chain. This allows the main control chip to access data from the N acquisition front-end units in real time when the daisy chain is in its first mode, continuously monitoring the daisy chain status. Each acquisition front-end unit detects the current status parameters of each cell in its corresponding battery pack. It detects the current daisy chain's operating status and, only when the main control chip is in sleep mode, periodically sends a heartbeat signal to the preceding acquisition front-end unit along the communication direction of the daisy chain. Within a preset time range, it monitors the heartbeat signal sent by the following acquisition front-end unit to determine the communication status with that unit. Based on the determination result, it controls whether to send an alarm signal to the power management chip through the bridge chip. Therefore, continuous monitoring of the daisy chain status is possible even when the main control chip is in sleep mode. Attached Figure Description

[0043] 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.

[0044] Figure 1 This is a schematic diagram showing the connection of each front-end unit in a daisy-chain communication diagnostic method according to an embodiment of the present invention.

[0045] Figure 2 This is a schematic diagram showing the connection of each front-end unit of the daisy-chain communication diagnostic method in another embodiment of the present invention;

[0046] Figure 3 This is a flowchart illustrating the communication diagnostic method of the daisy chain in an embodiment of the present invention;

[0047] Figure 4 This is a timing diagram of the operation of each front-end unit in a daisy-chain communication diagnostic method in another embodiment.

[0048] Figure 5 This is a schematic diagram of the structure of a battery management system in one embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of the structure of the battery management system in another embodiment of the present invention;

[0050] Explanation of reference numerals in the attached figures:

[0051] 11-Front-end unit;

[0052] 31-Data Acquisition Front-End Unit;

[0053] 41-Battery pack;

[0054] MCU - Main control chip;

[0055] BRIDGE - a bridging chip;

[0056] PMIC - Power Management Chip. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0058] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or front-end units is not necessarily limited to those steps or front-end units explicitly listed, but may include other steps or front-end units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0060] Given that it is difficult to continuously monitor the daisy-chain status while the system is in sleep mode in existing technologies, this invention provides a daisy-chain communication diagnostic method. The method diagnoses the communication of the daisy chain by determining its operating mode. If the operating mode is the first mode, N front-end units are accessed in real time, starting from the front-end unit connected to the bridging chip. The daisy-chain communication is considered normal only if N front-end units are accessed; otherwise, it is considered faulty. If the operating mode is the second mode, each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain. The heartbeat signal sent by the following front-end unit is monitored within a preset time. Only when a heartbeat signal from the following front-end unit is detected is the communication between that front-end unit and the following front-end unit considered normal, and the preset time is reset; otherwise, it is considered faulty, and an alarm signal is sent to the bridging chip. This allows for continuous monitoring of the daisy-chain status while the system is in sleep mode.

[0061] Furthermore, by applying this daisy-chain communication diagnostic method to the battery management system and devices, the present invention enables continuous monitoring of the daisy-chain status when the main control chip is in sleep mode.

[0062] This invention provides a daisy-chain communication diagnostic method for... Figures 1-2 The daisy chain shown is used for communication diagnostics. The daisy chain includes a BRIDGE bridging chip and N front-end units 11 connected in sequence, where N is an integer greater than 1.

[0063] The method includes:

[0064] The working mode of the daisy chain is determined, wherein the working mode includes a first mode and a second mode;

[0065] Diagnose the communication of the daisy chain based on its operating mode; among which:

[0066] If the working mode is mode 1, then perform the following steps:

[0067] Real-time access to the N front-end units 11 starts from the front-end unit 11 connected to the BRIDGE bridging chip;

[0068] The communication status of the daisy chain is determined based on the access status. If N front-end units 11 are accessed, the communication of the daisy chain is determined to be in a normal state; otherwise, the communication of the daisy chain is determined to be in a fault state.

[0069] If the working mode is the second mode, then perform the following steps:

[0070] Each front-end unit 11 periodically sends a heartbeat signal to the preceding front-end unit 11 along the communication direction of the daisy chain;

[0071] The heartbeat signal sent by the next front-end unit 11 is monitored within a preset time.

[0072] The communication status of the daisy chain is determined based on the monitoring situation. If the heartbeat signal sent by the next front-end unit 11 is detected, the communication between the front-end unit 11 and the next front-end unit 11 is determined to be in a normal state, and the preset time is reset; otherwise, the communication between the front-end unit 11 and the next front-end unit 11 is determined to be in a fault state, and an alarm signal is sent to the BRIDGE chip.

[0073] For ease of identification, the heartbeat signal can be a special waveform signal, such as a triangular wave. However, the present invention does not limit the waveform of the heartbeat signal, and those skilled in the art can choose other waveforms according to the actual situation.

[0074] For one specific implementation method, please refer to Figure 3 In practical use, the embodiments of the present invention provided, such as Figures 1-2 To perform communication diagnostics on the daisy chain shown, follow these steps:

[0075] S21: Power on;

[0076] The daisy chain is functioning normally;

[0077] S22: Determine the working mode of the daisy chain;

[0078] Specifically, the operating mode of the daisy chain is determined, and the communication of the daisy chain is diagnosed according to the operating mode. If the daisy chain receives a data read signal, the operating mode is determined to be the first mode, and proceed to S23; otherwise, the operating mode is determined to be the second mode, and proceed to S25.

[0079] S23: Start accessing the N front-end units 11 in real time from the front-end unit 11 connected to the BRIDGE chip;

[0080] Specifically, starting from the first front-end unit 11 connected to the first end of the BRIDGE chip, data from the first front-end unit 11 to the Nth front-end unit 11 is read sequentially along the communication direction of the daisy-chain network;

[0081] S24: Determine the communication status of the daisy chain based on the access information;

[0082] Specifically, if the number of accessed front-end units 11 is N, the daisy chain communication is determined to be in a normal state; otherwise, the daisy chain communication is determined to be in a fault state; and the process returns to S22.

[0083] S25: Each front-end unit 11 periodically sends a heartbeat signal to the previous front-end unit 11 along the communication direction of the daisy chain, and proceeds to S26.

[0084] S26: Determine the communication status of the daisy chain based on the access status;

[0085] Specifically, if the heartbeat signal sent by the next front-end unit 11 is detected, it is determined that the communication between the front-end unit 11 and the next front-end unit 11 is in a normal state, and the preset time is reset and returned to S22; otherwise, it is determined that the communication between the front-end unit 11 and the next front-end unit 11 is in a fault state and proceeds to S27.

[0086] S27: Send an alarm signal to the bridging chip BRIDGE.

[0087] Because daisy chains can be linked together to form a single-chain daisy chain structure (such as...) Figure 1 ) can also form daisy chain networks (such as Figure 2 In one embodiment, before step S25, the following step is further included:

[0088] The access type of the daisy chain is determined, including one-way access and two-way access.

[0089] In this case, if the access type is one-way access, step S25 may specifically include selecting the farthest sampling unit accessible by the BRIDGE chip as the top unit of the daisy chain, and starting from the top unit, each front-end unit 11 periodically sends a heartbeat signal to the previous front-end unit 11.

[0090] If the access type is bidirectional access, step S25 may specifically include: selecting the (i-1)th front-end unit 11 as the first top unit, and between the first front-end unit 11 and the (i-1)th front-end unit 11 in the daisy chain, each front-end unit 11 periodically sending the heartbeat signal to the previous front-end unit 11; and selecting the i-th front-end unit 11 as the second top unit, and between the i-th front-end unit 11 and the N-th front-end unit 11 in the daisy chain, each front-end unit 11 periodically sending the heartbeat signal to the next front-end unit 11, where i is an integer and 1 < i < N.

[0091] If the access type is bidirectional access, in one example, step S23 may specifically include reading data from the first front-end unit 11 to the Nth front-end unit 11 sequentially along the communication direction of the daisy-chain network, starting from the first front-end unit 11 connected to the first end of the BRIDGE chip, and sending the data to the second end of the BRIDGE chip.

[0092] Of course, the daisy chain access type in this invention is not limited to accessing the data in the N front-end units 11 in a single communication direction. Those skilled in the art can choose other real-time access methods according to the actual situation, such as simultaneously accessing the N front-end units 11 in real time from the two front-end units 11 connected to the two ends of the BRIDGE chip.

[0093] To ensure that the timing of heartbeat signal transmission by each front-end unit 11 is controllable, as a further preferred embodiment, after determining the access type of the daisy chain and before each front-end unit 11 periodically transmits a heartbeat signal to the preceding front-end unit 11 along the communication direction of the daisy chain, the following steps are further included:

[0094] Each front-end unit 11 is inspected after a set time.

[0095] The cumulative number of inspections is calculated. When the number of inspections reaches J, a heartbeat signal is sent to the previous front-end unit 11; where J is a positive integer and J≥1.

[0096] After sending a heartbeat signal to the previous front-end unit 11, the number of inspections is reset.

[0097] As a further preferred embodiment, the time required for J inspections is less than the preset time.

[0098] Specifically, the interval between sending heartbeat signals is less than the preset time. In a preferred embodiment, the preset time uses a large number decision mechanism to ensure that the daisy chain does not misjudge alarms. That is, the preset time is set to the time required for N*J inspections. During the preset time, the heartbeat signal sent by the next front-end unit is monitored. If the heartbeat signal sent by the next front-end unit is detected within the preset time, the communication between the front-end unit and the next front-end unit is determined to be normal, and the preset time is reset. If the heartbeat signal sent by the next front-end unit is not detected within the preset time, the communication between the front-end unit and the next front-end unit is determined to be faulty, and an alarm signal is sent to the bridging chip.

[0099] Now combined Figure 4 The timing diagram shown is for Figures 1-2The working principle of the second mode of the daisy chain is described in detail below:

[0100] The second mode of the daisy chain will now be further explained using two front-end units connected sequentially in the same communication direction as an example.

[0101] exist Figure 4 In the example shown, the second front-end unit periodically sends a heartbeat signal to the first front-end unit (not shown, indicating that the first front-end unit periodically sends a heartbeat signal to the previous front-end unit). When the number of inspections reaches 3, the second front-end unit sends a heartbeat signal to the first front-end unit. Since the inspection time of each front-end unit is not necessarily synchronized, the time when each front-end unit sends a heartbeat signal to the previous front-end unit is also not necessarily synchronized. To ensure that the heartbeat signal sent by the next front-end unit can be monitored, the time required for J inspections must be less than the preset time. If the heartbeat signal sent by the second front-end unit is detected within the preset time, the communication between the first front-end unit and the second front-end unit is determined to be in a normal state, and the preset time is reset; otherwise, the communication between the first front-end unit and the second front-end unit is determined to be in a fault state, and an alarm signal is sent to the BRIDGE chip.

[0102] For one specific implementation method, please refer to Figure 5 This invention provides a battery management system that employs the features provided in the embodiments of the present invention. Figure 3 The daisy-chain communication diagnostic method shown is used to determine the communication status of the daisy chain, including: a main control chip MCU, a bridge chip BRIDGE, a power management chip PMIC, N acquisition front-end units 31 and N battery packs 41, where N is an integer greater than 1.

[0103] The first and second terminals of the power management chip (PMIC) are respectively coupled to the first terminal of the main control chip (MCU) and the first terminal of the bridge chip (BRIDGE). The second terminal of the main control chip (MCU) is coupled to the second terminal of the bridge chip (BRIDGE). The third terminal of the bridge chip (BRIDGE) is coupled to the first acquisition front-end unit 31. The N acquisition front-end units 31 are electrically connected sequentially, and each acquisition front-end unit 31 is correspondingly coupled to a battery pack 41, forming the daisy chain.

[0104] The main control chip MCU is used to access the data of the N acquisition front-end units 31 in real time when the daisy chain is in the first mode;

[0105] Each acquisition front-end unit 31 is configured to: detect the current status parameters of each cell of the corresponding battery pack 41; detect the current working status of the daisy chain; periodically send a heartbeat signal to the preceding acquisition front-end unit 31 along the communication direction of the daisy chain only when the main control chip MCU is in sleep mode; and monitor the heartbeat signal sent by the following acquisition front-end unit 31 within a preset time range to determine the communication status with the following acquisition front-end unit 31; and control whether to send an alarm signal to the power management chip PMIC through the bridging chip BRIDGE based on the determination result.

[0106] The power management chip (PMIC) is used to wake up the main control chip (MCU) when it receives the alarm signal.

[0107] The battery pack 41 contains several batteries connected in series. Each data acquisition front-end unit 31 can detect the current state parameters of the corresponding batteries in the battery pack 41. The current state parameters can be the battery temperature, voltage, current, etc.

[0108] This is because the main control chip MCU can continuously read the data collected by the N acquisition front-end units 31 in normal working state (i.e., the daisy chain is in the first mode) to determine whether there is a communication interruption in the daisy chain at any time. However, when the main control chip MCU is in sleep state, it stops reading the data collected by the N acquisition front-end units 31, making it difficult to monitor whether there is a communication fault in the daisy chain. Therefore, the acquisition front-end unit 31 actively sends a heartbeat signal to the previous acquisition front-end unit 31 along the communication direction of the daisy chain, and monitors the heartbeat signal sent by the next acquisition front-end unit 31 within a preset time range to determine the communication status with the next acquisition front-end unit 31. Based on the determination result, it controls whether to send an alarm signal to the power management chip PMIC through the bridging chip BRIDGE. Thus, the daisy chain status can be continuously monitored when the main control chip MCU is in sleep state.

[0109] Specifically, the acquisition front-end unit 31 is used to: monitor the heartbeat signal sent by the next acquisition front-end unit 31 within a preset time range, so as to determine whether the corresponding acquisition front-end unit 31 has a communication failure.

[0110] If the heartbeat signal is received from the next acquisition front-end unit 31 within the preset time range, it is determined that the communication with the next acquisition front-end unit 31 is in a normal state, and the preset time is reset; otherwise, it is determined that the communication with the next acquisition front-end unit 31 is in a fault state, and an alarm signal is sent to the BRIDGE chip.

[0111] To facilitate fault detection, in one embodiment, the main control chip MCU is also used to view the error information in the alarm signal when it is woken up. In another embodiment, when the acquisition front-end unit 31 determines that the communication with the next acquisition front-end unit 31 is in a fault state, it sends an alarm signal to the power management chip PMIC and the main control chip MCU through the bridging chip BRIDGE.

[0112] In order to detect the communication status of the acquisition front-end unit 31 connected to the bridging chip BRIDGE, the bridging chip BRIDGE can also monitor the heartbeat signal sent by the first acquisition front-end unit 31 within a preset time range to determine the communication status between the bridging chip BRIDGE and the first acquisition front-end unit 31 connected to it.

[0113] In one embodiment, the BRIDGE chip is further used to convert the data pulse signal sent by the main control chip MCU into a corresponding isolated communication data encoding signal.

[0114] The isolated communication data encoding signal is the signal transmitted between the acquisition front-end units 31. Of course, the signal sent by the main control chip MCU can be an SPI interface signal, and the isolated communication data encoding signal can be an ISO code. Any foreseeable signal code type used is within the protection scope of this invention.

[0115] In practical use, when the main control chip MCU is in sleep mode, the daisy chain can be set to a low-power state to save power. Specifically, the acquisition front-end unit 31 can be set to be in sleep mode when not accessing data, and to enter a brief preparation state when receiving a heartbeat signal from the next acquisition front-end unit 31, resetting the preset time. The details are as follows:

[0116] Please refer to Figure 5 The daisy chain is a single-chain daisy chain, and its access type is unidirectional. In actual use, in order to detect the connection between the acquisition front-end units 31, the main control chip MCU can select the farthest acquisition front-end unit 31 that can be accessed by the bridging chip BRIDGE as the top unit of the daisy chain. Starting from the top unit being in sleep state, each acquisition front-end unit 31 periodically sends a heartbeat signal to the previous acquisition front-end unit 31.

[0117] In one specific implementation, the acquisition front-end unit 31 includes at least a loop counter, a heartbeat status register, a heartbeat detection counter, and a patrol counter; the bridging chip BRIDGE includes at least the heartbeat status register and the heartbeat detection counter; wherein:

[0118] The inspection counter is used by the data acquisition front-end unit 31 to inspect the corresponding battery pack 41 after a set time.

[0119] The cycle counter is used to accumulate the number of inspections;

[0120] The heartbeat detection counter is used to monitor the heartbeat signal sent by the next acquisition front-end unit 31 within a preset time; and when the heartbeat signal sent by the next acquisition front-end unit 31 is detected, the preset time is reset.

[0121] The heartbeat status register is used to determine that the communication between the acquisition front-end unit 31 and the next acquisition front-end unit 31 is normal when the heartbeat detection counter detects the heartbeat signal sent by the next acquisition front-end unit 31; otherwise, it determines that the communication between the acquisition front-end unit 31 and the next acquisition front-end unit 31 is faulty, and sends an alarm signal to the power management chip PMIC through the bridging chip BRIDGE.

[0122] In this situation, when any acquisition front-end unit 31 receives the heartbeat signal, it will be in the preparation state briefly, and after resetting the heartbeat detection counter, it will enter the sleep state and keep the state of the heartbeat status register unchanged; otherwise, the state of the heartbeat status register will be controlled to the alarm state, the corresponding acquisition front-end unit 31 will be in the working state, and an alarm signal will be sent to the power management chip PMIC through the bridging chip BRIDGE.

[0123] In one specific implementation, when the heartbeat detection counter detects the heartbeat signal within a preset time, the state of the heartbeat status register is controlled to remain at 0; when the heartbeat detection counter fails to detect the heartbeat signal within the preset time, the state of the heartbeat status register is controlled to remain at 1, and an alarm signal is sent to the main control chip MCU so that the main control chip MCU can view the specific alarm reason.

[0124] Meanwhile, each acquisition front-end unit 31 enters the inspection state after a set time to inspect the corresponding battery pack 41. After the inspection is completed, it enters the sleep state. The inspection counter accumulates the number of inspections. When the number of inspections reaches J, the acquisition front-end unit 31 sends a heartbeat signal to the previous front-end unit 11 while inspecting the corresponding battery pack 41.

[0125] The bridging chip BRIDGE is used to detect the communication status between itself and the first acquisition front-end unit 31. If the heartbeat detection counter detects the heartbeat signal within a preset time, it controls the state of the heartbeat status register to remain unchanged. If the heartbeat detection counter does not detect the heartbeat signal within the preset time, it controls the state of the heartbeat status register to remain in an alarm state and sends an alarm signal to the power management chip PMIC.

[0126] In another implementation, please refer to Figure 6 The fourth terminal of the BRIDGE chip is coupled to the Nth acquisition front-end unit 31. The daisy chain forms a daisy chain ring network, and its access type can be bidirectional. To speed up communication diagnosis, in one embodiment, the main control chip MCU is further used to select the (i-1)th acquisition front-end unit 31 as the first top unit and the i-th acquisition front-end unit 31 as the second top unit, where i is an integer and 1 < i < N.

[0127] In this case, the acquisition front-end unit 31 periodically sends a heartbeat signal to the preceding acquisition front-end unit 31 along the communication direction of the daisy chain, specifically:

[0128] Between the first acquisition front-end unit 31 and the (i-1)th acquisition front-end unit 31 in the daisy chain, each acquisition front-end unit 31 periodically sends the heartbeat signal to the previous acquisition front-end unit 31; between the i-th acquisition front-end unit 31 and the N-th acquisition front-end unit 31 in the daisy chain, each acquisition front-end unit 31 periodically sends the heartbeat signal to the next acquisition front-end unit 31.

[0129] Similarly, to save power, the daisy-chain network can be set to a low-power state, the acquisition front-end unit 31 is in the sleep state when not accessing data, and is in the short-term preparation state when receiving a heartbeat signal sent by the next acquisition front-end unit 31, and the preset time is reset.

[0130] In addition, this invention also provides a device including the aforementioned battery management system. For example, the battery management system can be applied in new energy vehicles or in other devices and systems that require battery management.

[0131] In summary, this invention diagnoses daisy-chain communication by determining the daisy-chain's operating mode. If the operating mode is the first mode, N front-end units are accessed in real time, starting from the front-end unit connected to the bridging chip. The daisy-chain communication is considered normal only if N front-end units are accessed; otherwise, it is considered faulty. If the operating mode is the second mode, each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain. The heartbeat signal sent by the following front-end unit is monitored within a preset time. Only when a heartbeat signal from the following front-end unit is detected is the communication between that front-end unit and the following front-end unit considered normal, and the preset time is reset; otherwise, it is considered faulty, and an alarm signal is sent to the bridging chip. This allows for continuous monitoring of the daisy-chain status even when the system is in sleep mode.

[0132] Furthermore, by applying this daisy-chain communication diagnostic method to the battery management system and devices, the present invention enables continuous monitoring of the daisy-chain status when the main control chip is in sleep mode.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A daisy-chain communication diagnostic method, characterized in that, The daisy chain includes a bridge chip and N front-end units that are electrically connected in sequence, where N is an integer greater than 1; The method includes: The working mode of the daisy chain is determined, wherein the working mode includes a first mode and a second mode; Diagnose the communication of the daisy chain based on its operating mode; among which: If the working mode is mode 1, then perform the following steps: Real-time access to the N front-end units starts from the front-end unit connected to the bridging chip; The communication status of the daisy chain is determined based on the access status. If N front-end units are accessed, the communication of the daisy chain is determined to be in a normal state; otherwise, the communication of the daisy chain is determined to be in a fault state. If the working mode is the second mode, then perform the following steps: Each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain; The heartbeat signal sent by the next front-end unit is monitored within a preset time. The communication status of the daisy chain is determined based on the monitoring data. If a heartbeat signal is detected from the next front-end unit, the communication between the front-end unit and the next front-end unit is determined to be normal, and the preset time is reset. Otherwise, the communication between the front-end unit and the next front-end unit is determined to be faulty, and an alarm signal is sent to the bridging chip.

2. The daisy-chain communication diagnostic method according to claim 1, characterized in that, Before each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain, the method further includes: The access type of the daisy chain is determined, including one-way access and two-way access.

3. The daisy-chain communication diagnostic method according to claim 2, characterized in that, Each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain, specifically including: If the access type is one-way access, the farthest sampling unit that the bridging chip can access is selected as the top unit of the daisy chain. Starting from the top unit, each front-end unit periodically sends a heartbeat signal to the previous front-end unit. If the access type is bidirectional, the (i-1)th front-end unit is selected as the first top unit. Between the first and (i-1)th front-end units in the daisy chain, each front-end unit periodically sends the heartbeat signal to the previous front-end unit. The ith front-end unit is selected as the second top unit. Between the ith and Nth front-end units in the daisy chain, each front-end unit periodically sends the heartbeat signal to the next front-end unit, where i is an integer and 1 < i < N.

4. The daisy-chain communication diagnostic method according to claim 2, characterized in that, After determining the access type of the daisy chain and before each front-end unit periodically sends a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain, the method further includes: Each front-end unit is inspected after a set time. The cumulative number of inspections is calculated. When the number of inspections reaches J, a heartbeat signal is sent to the previous front-end unit; where J is a positive integer and J≥1. After sending a heartbeat signal to the previous front-end unit, reset the number of inspections.

5. The daisy-chain communication diagnostic method according to claim 4, characterized in that, The time required for J inspections is less than the preset time.

6. A battery management system for implementing the daisy-chain communication diagnostic method according to any one of claims 1 to 5, characterized in that, include: The system consists of a main control chip, a bridge chip, a power management chip, N front-end units, and N battery packs, where N is an integer greater than 1. The first and second terminals of the power management chip are respectively coupled to the first terminal of the main control chip and the first terminal of the bridge chip; the second terminal of the main control chip is coupled to the second terminal of the bridge chip; the third terminal of the bridge chip is coupled to the first front-end unit; the N front-end units are electrically connected sequentially, and each front-end unit is coupled to a battery pack, forming the daisy chain; wherein: The main control chip is used to access the data of the N front-end units in real time when the daisy chain is in the first mode; Each front-end unit is configured to: detect the current status parameters of each cell in the corresponding battery pack; detect the current working state of the daisy chain; periodically send a heartbeat signal to the preceding front-end unit along the communication direction of the daisy chain only when the main control chip is in sleep mode; and monitor the heartbeat signal sent by the following front-end unit within a preset time range to determine the communication status with the following front-end unit; and control whether to send an alarm signal to the power management chip through the bridging chip based on the determination result. The power management chip is used to wake up the main control chip when it receives the alarm signal.

7. The battery management system according to claim 6, characterized in that, The front-end unit is specifically used to: monitor the heartbeat signal sent by the next front-end unit within a preset time range, so as to determine whether the corresponding front-end unit has a communication failure; If the heartbeat signal sent by the next front-end unit is received within the preset time range, it is determined that the communication with the next front-end unit is in a normal state, and the preset time is reset. Otherwise, the communication with the next front-end unit is determined to be in a fault state, and an alarm signal is sent to the bridging chip.

8. The battery management system according to claim 7, characterized in that, The fourth terminal of the bridging chip is coupled to the Nth front-end unit.

9. The battery management system according to claim 8, characterized in that, The main control chip is also used to select the (i-1)th front-end unit as the first top unit and the i-th front-end unit as the second top unit, where i is an integer and 1 < i < N.

10. The battery management system according to claim 9, characterized in that, The front-end unit is further configured to: periodically send the heartbeat signal to the preceding front-end unit between the first front-end unit and the (i-1)th front-end unit in the daisy chain; and periodically send the heartbeat signal to the following front-end unit between the i-th front-end unit and the N-th front-end unit in the daisy chain.

11. The battery management system according to claim 6, characterized in that, The main control chip is also used to view the error information in the alarm signal when it is woken up.

12. The battery management system according to claim 6, characterized in that, The bridging chip is also used to convert the data pulse signal sent by the main control chip into the corresponding isolated communication data encoding signal.

13. A device, characterized in that, Includes the battery management system as described in any one of claims 6-12.

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