ECAS alarm system and method

Abstract

The present invention relates to an ECAS alarm device and discloses an ECAS alarm system and method. The ECAS alarm system comprises an instrument unit connected to an ECAS unit via a first connection unit; a power supply unit connected to the instrument unit via a second connection unit; an ECAS protection unit for protecting an ECAS MCU unit; an ECAS network voltage divider unit for dividing the voltage of the ECAS MCU unit; an ECAS low-side driver unit for driving the ECAS MCU unit; an instrument alarm display unit for displaying an alarm; an instrument voltage divider network unit for dividing the voltage of the instrument MCU unit; and an instrument protection unit for protecting the instrument MCU unit. The ECAS alarm system designed by the present invention enables the cab to promptly receive an alarm signal and determine the specific fault status when the power cord plug in the ECAS system wiring harness is forgotten or damaged, further improving vehicle driving safety.

Description

Technical Field

[0001] The present invention relates to an ECAS alarm device, and in particular to an ECAS alarm system and method. Background Art

[0002] Commercial vehicles have long been a high-incidence source of traffic accidents. Braking systems, as a crucial component of commercial vehicle safety, play an indispensable role. However, accidents involving brake system failure often occur due to prolonged braking after being fully loaded or overloaded.

[0003] Such as prior art 1: Patent No. CN201911198212.4; Patent name: Commercial vehicle brake disc high temperature alarm system and alarm method based on ECAS electronically controlled air suspension.

[0004] Such as prior art 2: Patent number: CN202011473436.4; Patent name: Brake and its brake shoe wear alarm mechanism, alarm method and EBS system.

[0005] In the prior art, if the power cord plug in the ECAS system harness is forgotten to be plugged in or is damaged by human beings, the cab cannot receive the alarm signal. Summary of the Invention

[0006] The present invention aims to solve the problem in the prior art that a cab cannot receive an alarm signal when a power cord plug in an ECAS system harness is forgotten to be plugged in or is damaged by human intervention. The invention provides an ECAS alarm system and method.

[0007] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0008] An ECAS alarm system comprises an instrument unit and an ECAS unit; the ECAS unit contains a power supply unit; the instrument unit is connected to the ECAS unit via a first connection unit; the power supply unit is connected to the instrument unit via a second connection unit; the ECAS unit comprises an ECAS MCU unit, an ECAS network voltage divider unit, an ECAS protection unit, and an ECAS low-side driver unit; the ECAS protection unit is used to protect the ECAS MCU unit; the ECAS network voltage divider unit divides the voltage of the ECAS MCU unit; the ECAS low-side driver unit is used to drive the ECAS MCU unit; the instrument unit comprises an instrument MCU unit, an instrument alarm display unit, an instrument voltage divider network unit, and an instrument protection unit; the instrument alarm display unit is used to display an alarm; the instrument voltage divider network unit is used to divide the voltage of the instrument MCU unit; and the instrument protection unit is used to protect the instrument MCU unit.

[0009] Preferably, the ECAS low-side driver unit includes a MOS transistor U11, a resistor R11, and a resistor R12; the G end of the MOS transistor U11 is connected to one end of the resistor R11, and the other end of the resistor R11 is connected to the output driver end of the ECAS MCU unit; the S end of the MOS transistor U11 is connected to one end of the resistor R12 and the first connecting unit, and the other end of the resistor R12 is grounded.

[0010] Preferably, the ECAS network voltage divider unit includes resistors R1, R2, and R3; one end of the resistor R1 is connected to the ignition power supply terminal of the power supply unit and the D terminal of the MOS tube U11; the other end of the resistor R1 is connected to the resistor R2, the first connection unit, and the voltage terminal of the ECAS MCU unit A00; the other end of the resistor R2 is connected to the resistor R3, and the other end of the resistor R3 is grounded.

[0011] Preferably, the instrument alarm display unit includes a resistor R21, a resistor R22 and a light emitting diode LED1; the resistor R22 and the light emitting diode LED1 are connected in parallel to each other and then connected in series with the resistor R21.

[0012] Preferably, the instrument voltage divider network unit includes resistor R31, resistor R32 and resistor R33; one end of resistor R31 is connected to the ignition power supply end of the power supply unit, and the other end is connected to the instrument alarm display unit, the first connection unit and the instrument MCU unit Y00 voltage end; the other end of resistor R32 is connected to resistor R33 and the instrument protection unit; the other end of resistor R33 is grounded.

[0013] Preferably, the second connection unit includes an ignition power connection port, a battery power connection port, a ground connection port and a CAN bus connection port; the ignition power connection port is used to connect the power supply unit and the ignition power supply; the battery power connection port is used to connect the battery power and the power supply unit; the ground connection port is used to connect the ground wire and the power supply unit; the CAN bus connection port is used to connect the instrument unit and the power supply unit.

[0014] Preferably, the first connection unit includes an alarm connection port and a ground port, one end of the alarm connection port is connected to the instrument alarm display unit and the other end is connected to the ECAS network voltage divider unit and the ECAS low-side drive unit; one end of the ground port is connected to the ground and the other end is connected to the ECAS low-side drive unit.

[0015] In order to solve the above technical problems, the present invention further provides an ECAS alarm method, which is implemented by the ECAS alarm system and includes controlling the instrument unit alarm and the ECAS unit alarm.

[0016] Preferably, the control of the ECAS unit alarm includes: collecting CAN bus information within a unit time T;

[0017] The voltage of the voltage terminal A00 of the ECAS MCU unit is collected within the unit time T to obtain the voltage VA;

[0018] The power-on time T1 is calculated by the time when the voltage at the A00 terminal of the ECAS MCU unit is powered on.

[0019] The ECAS MCU unit state mode is determined by comparing the power-on time T1 with a set first time threshold.

[0020] Preferably, the control of the instrument unit alarm includes:

[0021] The voltage VY is obtained by collecting the voltage terminal voltage of the instrument MCU unit Y00 within the unit time;

[0022] The power-on time T0 is calculated by the time when the voltage at the voltage terminal Y00 of the instrument MCU unit is powered on.

[0023] The meter unit state mode is determined by comparing the power-on time T0 with the set second time threshold to determine the ECASMCU unit state mode.

[0024] The present invention has significant technical effects due to the adoption of the above technical solutions:

[0025] The ECAS alarm system designed by the present invention can receive an alarm signal in time in the cab and determine the specific fault status when the power cord plug in the ECAS system wiring harness is forgotten to be inserted or is damaged, thereby further improving the safety of driving the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the electrical control diagram of the system of the present invention.

[0027] Figure 2 Flowchart of Example 2 of the present invention.

[0028] Figure 3 This is a flow chart of Example 3 of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0030] Example 1

[0031] An ECAS alarm system comprises an instrument unit and an ECAS unit; the ECAS unit contains a power supply unit; the instrument unit is connected to the ECAS unit via a first connection unit; the power supply unit is connected to the instrument unit via a second connection unit; the ECAS unit comprises an ECAS MCU unit, an ECAS network voltage divider unit, an ECAS protection unit, and an ECAS low-side driver unit; the ECAS protection unit is used to protect the ECAS MCU unit; the ECAS network voltage divider unit divides the voltage of the ECAS MCU unit; the ECAS low-side driver unit is used to drive the ECAS MCU unit; the instrument unit comprises an instrument MCU unit, an instrument alarm display unit, an instrument voltage divider network unit, and an instrument protection unit; the instrument alarm display unit is used to display an alarm; the instrument voltage divider network unit is used to divide the voltage of the instrument MCU unit; and the instrument protection unit is used to protect the instrument MCU unit.

[0032] Figure 1 In the embodiment, the ECAS low-side driver unit includes a MOS transistor U11, a resistor R11, and a resistor R12; the G terminal of the MOS transistor U11 is connected to one end of the resistor R11, and the other end of the resistor R11 is connected to the output driver end of the ECAS MCU unit; the S terminal of the MOS transistor U11 is connected to one end of the resistor R12 and the first connecting unit, and the other end of the resistor R12 is grounded.

[0033] The ECAS network voltage divider unit includes resistors R1, R2, and R3. One end of resistor R1 is connected to the ignition power supply terminal of the power supply unit and the D terminal of MOS tube U11. The other end of resistor R1 is connected to resistor R2, the first connection unit, and the voltage terminal of ECAS MCU unit A00. The other end of resistor R2 is connected to resistor R3, and the other end of resistor R3 is grounded.

[0034] The ECAS protection unit includes a resistor R4 and a capacitor C1. R4 is a current-limiting resistor and C1 is a filter capacitor. The resistor R4 is connected to the MCU_ANA_A port of the ECAS MCU unit, and the other end is connected to the resistor R3, the resistor R2, and the capacitor C1. The other end of the capacitor C1 is grounded.

[0035] Resistors R2 and R3 are designed to ensure that the voltage on the ECAS MCU's AD acquisition port MCU_ANA_A within the valid ignition power input range does not exceed the ECAS MCU's operating voltage, with a certain margin. R4 is a current-limiting resistor, and C1 is a filter capacitor. When the first connection unit is properly inserted, the instrument alarm display unit is connected to ground through both R2 and R3. R2 and R3 act as current-limiting resistors, and the sum of the resistances of R2 and R3 is designed to be significantly greater than R1 and the instrument unit's resistor R21. Specifically, (R2 + R3) ≥ 30 * R21, R21 = 2 * R1, R2 = R32, and R3 = R33. The ECAS MCU uses the voltage on MCU_ANA_A to calculate the voltage VA at the ECAS MCU's A00 port and the status information of the first connection unit J1 in the ECAS MCU, as well as the power-on time T1, obtained from the CAN bus, to determine the ECAS mode.

[0036] The instrument alarm display unit includes resistors R21 and R22, and LED1. Resistor R22 and LED1 are connected in parallel, then in series with resistor R21. R21 is a current-limiting resistor, calculated based on the rated current of the LED and the ignition power supply voltage. R22 is a shunt resistor.

[0037] The meter protection unit includes resistor R34, a current-limiting resistor, and capacitor C31, a filter capacitor. Resistor R34 is connected to the MCU_ANA_Y port of the meter MCU unit, with its other end connected to resistors R33, R32, and C31. The other end of capacitor C31 is grounded. Ground is connected through R32 and R33, which act as current-limiting resistors. The combined resistance of R32 and R33 is designed to be significantly greater than that of R21 and the ECAS ECU pull-up resistor R1. It is recommended that (R32 + R33) ≥ 30 * R21, R21 = 2 * R1, and R31 ≥ 100 * R21. This ensures that LED1 does not dim when the voltage on connector pin 9 is high.

[0038] The instrument voltage divider network unit includes resistor R31, resistor R32 and resistor R33; one end of resistor R31 is connected to the ignition power supply end of the power supply unit, and the other end is connected to the instrument alarm display unit, the first connection unit and the instrument MCU unit Y00 voltage end; the other end of resistor R32 is connected to resistor R33 and the instrument protection unit; the other end of resistor R33 is grounded.

[0039] The instrument alarm display unit and R31, R32, and R33 form a voltage divider network for detecting the voltage VY at the Y00" port of the instrument MCU unit. Resistors R32 and R33 are designed to ensure that the voltage at the AD acquisition port MCU_ANA_Y of the instrument MCU within the effective input range of the ignition power supply does not exceed the MCU's operating voltage, and a certain margin is left.

[0040] The second connection unit J2 includes an ignition power connection port, a battery power connection port, a ground connection port and a CAN bus connection port; the ignition power connection port is used to connect the power unit and the ignition power; the battery power connection port is used to connect the battery power and the power unit; the ground connection port is used to connect the ground and the power unit; the CAN bus connection port is used to connect the instrument unit and the power unit.

[0041] The first connection unit J1 includes an alarm connection port X1-9 and a ground port X1-15. One end of the alarm connection port, X1-9, is connected to the instrument alarm display unit, while the other end, X1-9, is connected to the ECAS network voltage divider and the ECAS low-side driver unit. One end, X15, of the ground port is connected to ground, while the other end, X1-15, is connected to the ECAS low-side driver unit. X1-15 is connected to the S-terminal of the MOSFET U11 and resistor R11 of the ECAS low-side driver unit.

[0042] Example 2

[0043] Based on the first embodiment, an ECAS alarm method is provided. The method implemented by the ECAS alarm system includes controlling the instrument unit alarm and controlling the ECAS unit alarm.

[0044] Example 3

[0045] Based on the above embodiment, the control of the ECAS unit alarm in this embodiment includes: collecting CAN bus information within a unit time T;

[0046] The voltage of the voltage terminal A00 of the ECAS MCU unit is collected within the unit time T to obtain the voltage VA;

[0047] The power-on time T1 is calculated by the time when the voltage at the A00 terminal of the ECAS MCU unit is powered on.

[0048] The ECAS MCU unit state mode is determined by comparing the power-on time T1 with a set first time threshold.

[0049] Resistors R1, R2, and R3 form a voltage divider network for detecting the voltage VA of the A00 port of the ECAS MCU unit.

[0050] Resistors R2 and R3 are designed to ensure that the voltage on the ECAS MCU's AD acquisition port MCU_ANA_A does not exceed the MCU's operating voltage within the effective input range of the ignition power supply, with a certain margin. Assuming the ECAS ECU is a 24V system with a general power supply voltage range of 18V to 32V, when the voltage obtained by dividing the voltage across R3 is greater than or equal to 5V, the ECAS MCU uniformly identifies it as 5V. Leaving a certain margin means that when the voltage is 32V, the voltage obtained by dividing the voltage across R3 is slightly less than 5V, for example, 4.5V.

[0051] R4 is a current-limiting resistor, and C1 is a filter capacitor. When J1 is properly inserted, the alarm indication circuit is connected to ground through R2 and R3. R2 and R3 act as current-limiting resistors. The sum of the resistances of R2 and R3 should be designed to be significantly greater than R1 and R21 on the instrument panel. (Recommended) (R2 + R3) ≥ 30 * R21, R21 = 2 * R1, R2 = R32, and R3 = R33. The ECAS MCU calculates the voltage VA at the "A00" port based on the voltage on MCU_ANA_A, obtains "ECAS J1 status" information from the CAN bus, and receives power-on time T1 to determine whether the ECAS is in self-test mode, internal fault mode, J1 disconnected mode, or other fault modes.

[0052] NMOS transistor U11, resistors R11, and R12 form a low-side driver module, used to drive the alarm indicator circuit on the instrument. R11 is a current-limiting resistor; R12 is a voltage-divider resistor, which comes into effect when the first connection unit J1 is unplugged. R12 = 0.05 * R1. The NMOS transistor is the driver transistor.

[0053] R1=1K, R2=R32=50K, R3=R4=R33=R34=10K, R11=R12=50Ω, R21=R22=2K, R31=200K.

[0054] Assume that the voltage collected by MCU_ANA_A of the AD port of the ECAS ECU MCU is Vx2, then the voltage of the ECAS ECU "A00" port VA = (R2+R3) / R3 = 6*Vx2.

[0055] ECAS state 1: The first connection unit J1 is normally inserted. When the output control terminal OUTDRV_X1-9 of the ECAS ECU unit outputs 5V, the D and S stages of U11 are turned on, and the ground wire is connected to the ground wire through the ground wire of the vehicle instrument unit. R12 does not participate in the voltage division, and X1-9 outputs a low level. At this time, the collected voltage VA = 0V. A voltage threshold VA0 slightly larger than the minimum 0V is set, and VA0 is set to 0.01*Vig; at this time, VY = VA ≤ VA0.

[0056] ECAS state 2: The first connection unit J1 is normally inserted. When the output control terminal OUTDRV_X1-9 of the ECAS ECU unit outputs 0V, the voltage VA collected at this time is the voltage of the two voltage divider networks at the vehicle instrument end and the ECAS ECU unit end. VA=VY≈0.974*Vig. The calculation process is shown in state B. The threshold VY2=0.95*Vig. At this time, VA=VY≥VY2;

[0057] ECAS state 3: The first connection unit J1 is unplugged. When the output control terminal UTDRV_X1-9 of the ECAS ECU unit outputs 5V, the D and S stages of U11 are turned on. The conduction voltage drop Vds between the D and S stages of the NMOS tube U11 is ≈0V, and is connected to the ground line through the resistor R12. The resistor R12 participates in the voltage division. Because (R2+R3)≥60*R1, R12=0.05*R1, so the resistor R1 is negligible relative to (R2+R3), VA≈R12 / (R1+R12)*Vig, and the unplugging low-level threshold VA1 is set to 0.04*Vig; at this time, 3*VA1≥VA≥VA1

[0058] ECAS state 4: When the first connection unit J1 is unplugged and the output control terminal OUTDRV_X1-9 of the ECAS ECU outputs 0V, the collected voltage VA≈(R2+R3) / (R1+R2+R3)*Vig=0.984*Vig. At this time, VA≥VY2. At this time, VA is difficult to distinguish from the voltage in "ECAS state 2". It is necessary to combine the J1_Pulling_out_Fault_bit in the "ECAS fault status" message sent by the vehicle instrument on the CAN bus to make a judgment. ECAS ECU alarm control flow chart Figure 2 .

[0059] Self-test mode: The ECAS ECU is in self-test mode for the first 2 seconds. The output control terminal OUTDRV_X1-9 of the ECAS ECU MCU outputs 1, that is, 5V. The MCU of the ECAS ECU is a 5V system.

[0060] Internal fault mode: When there is other internal fault inside the ECAS ECU, such as sensor failure, the MCU inverts the output control terminal OUTDRV_X1-9 every 0.1 seconds, that is, outputs a square wave with a period of 0.2 seconds;

[0061] First connection unit J1 pull-out mode: 2 seconds before power-on, if 3*VA1≥VA≥VA1, the first connection unit J1 is determined to be in pull-out mode. After the self-test mode ends, a preliminary judgment is made based on the J1_Pulling_out_Fault_bit in the "ECAS fault status" message. When J1_Pulling_out_Fault_bit=1, OUTDRV_X1-9 is set to 1, that is, 5V is output. When 3*VA1≥VA≥VA1, J1 is determined to be in pull-out mode.

[0062] Other failure modes: VA is other voltages.

[0063] Example 4

[0064] Based on the above embodiment, the control of the instrument unit alarm in this embodiment includes:

[0065] The voltage VY is obtained by collecting the voltage terminal voltage of the instrument MCU unit Y00 within the unit time;

[0066] The power-on time T0 is calculated by the time when the voltage at the voltage terminal Y00 of the instrument MCU unit is powered on.

[0067] The meter unit state mode is determined by comparing the power-on time T0 with the set second time threshold to determine the ECASMCU unit state mode.

[0068] Resistor R21, resistor R22 and light-emitting diode LED1 constitute the instrument alarm display unit; after the instrument unit is powered on, when the voltage at pin 9 of the first connection unit J1-connector is low, the light-emitting diode LED1 lights up; when the voltage at pin 9 of the connector J1 is high, the light-emitting diode LED1 lights up and goes out. R21 is a current-limiting resistor, calculated based on the rated current of the light-emitting diode and the ignition power supply voltage; R22 is a shunt resistor, preventing the light-emitting diode LED1 from dimming when the voltage at pin 9 of the first connection unit J1 is high, R22 = R21. The instrument alarm display unit is grounded through resistors R32 and R33. Resistors R32 and R33 are current-limiting resistors. The sum of the resistance values of resistors R32 and R33 is designed to be much larger than R21 and the pull-up resistor R1 at the ECAS ECU unit end.

[0069] (R32+R33)≥30*R21, R21=2*R1, R31≥100*R21;

[0070] This ensures that the light emitting diode LED1 will not dim when the voltage at the pin 9 of the first connection unit is at a high level.

[0071] The instrument alarm display unit and resistors R31, R32 and R33 form a voltage divider network for detecting the voltage VY of the Y00 port of the instrument MCU unit.

[0072] Resistors R32 and R33 are designed to ensure that the voltage on the instrument MCU's AD acquisition port MCU_ANA_Y does not exceed the MCU's operating voltage within the effective input range of the ignition power supply, with a certain margin. R34 is a current-limiting resistor, and C31 is a filter capacitor.

[0073] The instrument unit MCU calculates the voltage VY of the instrument MCU unit Y00 port, the duration TC, and the power-on time T0 through the voltage on MCU_ANA_Y, thereby determining whether the ECAS ECU is in self-test mode, internal fault mode, J3 disconnection mode, J1 disconnection mode, or a hot plug event or other fault mode. See the automobile instrument alarm control flow chart for details. Figure 3 .

[0074] R1=1K, R2=R32=50K, R3=R4=R33=R34=10K, R11=R12=50Ω, R21=R22=2K, R31=200K.

[0075] When the light emitting diode LED1 is not conducting, the equivalent resistance RLED is greater than 1M. When it is connected in parallel with the resistance of R22, the equivalent parallel resistance R22a of R22 and the light emitting diode LED1 is ≈ 2K.

[0076] When the NMOS tube U11 is not conducting, the equivalent resistance RNMOS is greater than 10M, which can be ignored when connected in parallel with the resistors R2, R3, R32, and R33.

[0077] Assume that the voltage collected by "MCU_ANA_Y" of the AD port of the automobile instrument MCU is Vx1, then the voltage of the "instrument MCU unit Y00" port of the automobile instrument is VY = (R32 + R33) / R33 = 6*Vx1.

[0078] State A: The first connection unit J1 and the second connection unit J3 are normally inserted. When the output control terminal OUTDRV_X1-9 of the ECAS ECU outputs 5V, the D-stage and S-stage of the NMOS tube U11 are turned on, and the ground line is connected to the ground line through the ground line of the vehicle instrument. R12 does not participate in the voltage division, and X1-9 outputs a low level. At this time, the voltage VY of the Y00 port of the instrument MCU unit is 0V. A voltage threshold VA0 slightly larger than the minimum 0V is set. For example, VA0 can be set to 0.01*Vig; at this time, VY = VA ≤ VA0.

[0079] State B: The first and second connection units J1 and J3 are properly connected. When the ECAS ECU's output control terminal OUTDRV_X1-9 outputs 0V, X1-9 outputs a high level. At this point, the voltage VY at the "Instrument MCU Unit Y00" port is the combined voltage of the two voltage divider networks at the vehicle instrument panel and the ECAS ECU. RX2 represents the equivalent parallel resistance of (R32 + R33) and (R2 + R3), i.e., RS2 = (R32 + R33) / / (R2 + R3); RS2 represents the equivalent parallel resistance of (R21 + R22a), R1, and R31, i.e., RX2 = (R21 + R22a) / / R1 / / R31.

[0080] VY≈RX2 / (RS2+RX2)*Vig;

[0081] RX2=30K, RS2≈0.8K, VY≈0.974*Vig;

[0082] Set the voltage threshold VY2 = 0.95*Vig; at this time VY = VA ≥ VY2;

[0083] State C: The first connector J1 is properly plugged in, while the second connector J3 is unplugged. Since the second connector J3 provides voltage to the ECAS ECU, the ECAS ECU is inoperative, and the pull-up resistor R1 on the "Instrument MCU Unit Y00" port is ineffective. At this point, the voltage VY at the "Instrument MCU Unit Y00" port is the combined voltage of the two voltage divider networks at the vehicle instrument panel and the ECAS ECU. RX3 represents the equivalent parallel resistance of (R32 + R33) and (R2 + R3), i.e., RX3 = (R32 + R33) / / (R2 + R3).

[0084] RS3 represents the equivalent parallel resistance of (R21+R22a) and R31, that is, RS2=(R21+R22a) / / R31;

[0085] VY≈RX2 / (RS2+RX2)*Vig;

[0086] RX3=30K, RS3≈4K, VY≈0.882*Vig;

[0087] Set the voltage threshold VY3 = 0.85*Vig; at this time VY2>VY≥VY3;

[0088] State D: The first connection unit J1 is unplugged, J1-9 and J1-15 are short-circuited, LED1 is always on, and the voltage VY of the "Instrument MCU Unit Y00" port is VY=0V≤VA0 (threshold VA0=0.01*Vig)

[0089] Self-test mode: within 2.0 seconds after the instrument is powered on, VY≤VA0;

[0090] Normal mode: After the self-test mode, VY≥VY2, duration ≥0.2 seconds;

[0091] The second connection unit J3 is pulled out in mode: after the instrument is powered on, VY2>VY≥VY3;

[0092] Internal fault mode: 2.0 seconds after the instrument is powered on, within the next 0.2 seconds, VA ≥ VY2 for 0.1 seconds, VY ≤ VA0 for 0.1 seconds;

[0093] Unplug mode of the first connection unit J1: 2.0 seconds after the instrument is powered on, VY≤VA0, and the duration TC≥2.2s; Live plug-in event occurs: After the normal mode, VY≤VA0, and then VY≥VY2 after 2s;

[0094] Other failure modes: VY is other values.

[0095] The system collects the voltage Vx1 on the AD port "MCU_ANA_Y" every 0.02s and calculates the voltage VY of the "instrument MCU unit Y00" port. So if VY is 10 times in a row,

Claims

1. An ECAS alarm system, comprising an instrument unit and an ECAS unit; the ECAS unit includes a power supply unit; characterized in that: The instrument unit is connected to the ECAS unit via the first connecting unit; The power supply unit is connected to the instrument unit through the second connection unit; the ECAS unit includes an ECAS MCU unit, an ECAS network voltage divider unit, an ECAS protection unit and an ECAS low-side driver unit; The ECAS protection unit is used to protect the ECAS MCU unit; The ECAS network voltage divider unit divides the voltage of the ECAS MCU unit; The ECAS low-side driver unit is used to drive the ECAS MCU unit; The instrument unit includes the instrument MCU unit, the instrument alarm display unit, the instrument voltage dividing network unit and the instrument protection unit; The instrument alarm display unit is used for alarm display; The instrument voltage dividing network unit is used to divide the voltage of the instrument MCU unit; the instrument protection unit is used to protect the instrument MCU unit; The ECAS network voltage divider unit includes resistors R1, R2, and R3. One end of resistor R1 is connected to the ignition power supply terminal of the power supply unit and the D terminal of the MOS tube U11. The other end of resistor R1 is connected to resistor R2, the first connection unit, and the voltage terminal of the ECAS MCU unit A00. The other end of resistor R2 is connected to resistor R3, and the other end of resistor R3 is grounded. The instrument voltage divider network unit includes resistor R31, resistor R32 and resistor R33; one end of resistor R31 is connected to the ignition power supply end of the power supply unit, and the other end is connected to the instrument alarm display unit, the first connection unit and the instrument MCU unit Y00 voltage end; the other end of resistor R32 is connected to resistor R33 and the instrument protection unit; the other end of resistor R33 is grounded.

2. The ECAS alarm system according to claim 1, characterized in that: The ECAS low-side driver unit includes a MOS transistor U11, a resistor R11, and a resistor R12; the G terminal of the MOS transistor U11 is connected to one end of the resistor R11, and the other end of the resistor R11 is connected to the output driver end of the ECAS MCU unit; the S terminal of the MOS transistor U11 is connected to one end of the resistor R12 and the first connecting unit, and the other end of the resistor R12 is grounded.

3. The ECAS alarm system according to claim 1, characterized in that: The instrument alarm display unit includes a resistor R21, a resistor R22 and a light emitting diode LED1; the resistor R22 and the light emitting diode LED1 are connected in parallel with each other and then connected in series with the resistor R21.

4. The ECAS alarm system according to claim 1, characterized in that: The second connection unit includes an ignition power connection port, a battery power connection port, a ground connection port and a CAN bus connection port; the ignition power connection port is used to connect the power supply unit and the ignition power supply; the battery power connection port is used to connect the battery power and the power supply unit; the ground connection port is used to connect the ground wire and the power supply unit; the CAN bus connection port is used to connect the instrument unit and the power supply unit.

5. The ECAS alarm system according to claim 1, characterized in that: The first connection unit includes an alarm connection port and a grounding port. One end of the alarm connection port is connected to the instrument alarm display unit and the other end is connected to the ECAS network voltage divider unit and the ECAS low-side drive unit; one end of the grounding port is connected to the ground terminal and the other end is connected to the ECAS low-side drive unit.

6. An ECAS alarm method, characterized in that: The method implemented by the ECAS alarm system according to any one of claims 1 to 5 includes controlling the instrument unit alarm and controlling the ECAS unit alarm.

7. The ECAS alarm method according to claim 6, characterized in that: The control of ECAS unit alarms includes: CAN bus information collection, CAN bus information collection is performed within the unit time T; The voltage of the voltage terminal A00 of the ECAS MCU unit is collected within the unit time T to obtain the voltage VA; The power-on time T1 is calculated by the time when the voltage at the A00 terminal of the ECAS MCU unit is powered on. The ECAS MCU unit state mode is determined by comparing the power-on time T1 with a set first time threshold.

8. The ECAS alarm method according to claim 6, characterized in that: The control of the instrument unit alarm includes: The voltage VY is obtained by collecting the voltage terminal voltage of the instrument MCU unit Y00 within the unit time; The power-on time T0 is calculated by the time when the voltage at the voltage terminal Y00 of the instrument MCU unit is powered on. The meter unit state mode is determined by comparing the power-on time T0 with a set second time threshold to determine the ECAS MCU unit state mode.

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