Automobile intelligent chassis electric control system and control circuit thereof

Abstract

The invention relates to an electromagnetic valve fault diagnosis technology, and discloses an automobile intelligent chassis electric control system and a control circuit thereof, the automobile intelligent chassis electric control system comprises a first fault diagnosis circuit and a second fault diagnosis circuit, the first fault diagnosis circuit and the second fault diagnosis circuit respectively comprise a voltage collector, a voltage division circuit and a protection circuit; the protection circuit is used for protecting the fault diagnosis circuit, the voltage division circuit is used for dividing the voltage output by the electromagnetic valve, and the voltage collector is used for collecting the divided voltage; the voltage collector is used for collecting the voltage of the electromagnetic valve in real time; and determining the state of the electromagnetic valve according to the acquired voltage of the electromagnetic valve. Fault diagnosis of the electromagnetic valves of the intelligent chassis electric control system of the automobile can be carried out without driving the electromagnetic valves, only one port resource is needed for diagnosis of each electromagnetic valve, the diagnosis mode is simple, and the cost is low.

Description

Technical Field

[0001] The present invention relates to electromagnetic valve fault diagnosis technology, and in particular to an automobile intelligent chassis electronic control system and a control circuit thereof. Background Art

[0002] The electronically controlled dryer assembly with an ECU controller has a protective function that greatly extends the dryer's service life. The electronically controlled dryer body is equipped with an unloading solenoid valve and a backflush solenoid valve. Electrical failures may occur in these solenoid valves during use, thus affecting the function of the electronically controlled dryer.

[0003] For example, prior art 1: CN105549578B, an invention patent published on January 30, 2018, discloses a vehicle solenoid valve fault diagnosis response circuit and its use method, which includes a CPU, a solenoid valve, a logic operation processing circuit, an integrated chip and a display device. The logic operation processing circuit includes a NAND gate chip, a NOR gate chip, and a comparator.

[0004] In the prior art, the circuit is complex and the cost is high, and it can only determine whether the solenoid valve has a fault, but cannot determine the specific type of fault.

[0005] A fault can only be detected after the solenoid valve is driven by the integrated chip BTS7236W, that is, a fault can only be detected when the solenoid valve is working. However, the solenoid valve of the electronically controlled APU is not working most of the time, and the timeliness of the existing technical solution is poor.

[0006] Diagnosing each solenoid valve requires four ports: an information output port, a primary control signal output port, a secondary control signal output port, and a voltage input port. Diagnosing two solenoid valves requires eight ports. The electronically controlled APU (Air Processing Unit) adds management of different air paths to the electronically controlled dryer, achieving more precise and efficient air processing, significantly increasing the port resource requirements.

[0007] Electronically controlled APUs primarily use 24V systems, but 12V systems also exist. The solenoid valves used are classified into two categories: 24V and 12V. The resistance of a 24V solenoid valve is approximately 80Ω, while that of a 12V solenoid valve is approximately 20Ω. During installation, due to worker negligence, mixed installation of solenoid valves is possible. Therefore, diagnosis of mixed installation of solenoid valves cannot be performed. Summary of the Invention

[0008] The present invention aims to solve the problems in the prior art of poor diagnostic timeliness of solenoid valves and the large number of port resources required for diagnosis, and provides an automobile intelligent chassis electronic control system and a control circuit thereof.

[0009] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0010] A control circuit of an intelligent chassis electronic control system for an automobile, which includes a first fault diagnosis circuit and a second fault diagnosis circuit. Both the first fault diagnosis circuit and the second fault diagnosis circuit include a voltage collector, a voltage dividing circuit and a protection circuit. The protection circuit is used to protect the fault diagnosis circuit. The voltage dividing circuit is used to divide the voltage output by the solenoid valve. The voltage collector is used to collect the divided voltage. The fault diagnosis method for the solenoid valve of the commercial vehicle electronic control APU includes:

[0011] Collect the voltage of the solenoid valve in real time through the voltage collector; determine the state of the solenoid valve based on the collected voltage of the solenoid valve.

[0012] Preferably, the states of the solenoid valve include the solenoid valve short - circuit to ground state, the solenoid valve mis - assembly state, the solenoid valve normal state, the solenoid valve open - circuit state, and the solenoid valve short - circuit to power state.

[0013] Preferably, the first fault diagnosis circuit includes diode D1A, resistor R1A, diode D1B, resistor R1B and voltage collector AD1;

[0014] The anode of the diode D1A is connected to the input voltage U1. The cathode of the diode D1A is connected to one end of the resistor R1A. The other end of the resistor R1A is connected to the voltage collector AD1 and the anode of the diode D1B. The cathode of the diode D1B is connected to the resistor R1B and the solenoid valve output terminal OUT1. The other end of the resistor R1B is grounded.

[0015] The second fault diagnosis circuit includes diode D2A, resistor R2A, diode D2B, resistor R2B and voltage collector AD2;

[0016] The anode of the diode D2A is connected to the input voltage U2. The cathode of the diode D2A is connected to one end of the resistor R2A. The other end of the resistor R2A is connected to the voltage collector AD2 and the anode of the diode D2B. The cathode of the diode D2B is connected to the resistor R2B and the solenoid valve output terminal OUT2. The other end of the resistor R2B is grounded.

[0017] Preferably, when the resistor R1B is much larger than the first solenoid valve resistance, the voltage collected by the voltage collector AD1 is 0.5U1, and the state of the first solenoid valve is the solenoid valve normal state;

[0018] When the resistor R2B is much larger than the second solenoid valve resistance, the voltage collected by the voltage collector AD2 is 0.5U2, and the state of the second solenoid valve is the solenoid valve normal state.

[0019] Preferably, when the voltage collected by the voltage collector AD1 is the voltage drop at the diode D1B end, the state of the first solenoid valve is the solenoid valve short-circuited state to the ground; when the voltage collected by the voltage collector AD2 is the voltage drop at the diode D2B end, the state of the second solenoid valve is the solenoid valve short-circuited state to the ground.

[0020] As a preferred embodiment, the voltage collected by the voltage collector AD1 is U D1B +R 1B *I 1b ; Among them, R 1B is the resistance value of R1B, I 1b is the current flowing through; the state of the first solenoid valve is the solenoid valve open state; the voltage collected by the voltage collector AD2 is U D2B +R 2B *I 2b ; Among them, R 2B is the resistance value of R2B, I 2b is the current flowing through; the state of the second solenoid valve is the solenoid valve open state.

[0021] As a preferred embodiment, the voltage collected by the voltage collector AD1 is U1-U D1A -R 1A *I 1a ; Among them, R 1A is the resistance value of R1A, I 1a The state of the first solenoid valve is the solenoid valve short circuit state to the power supply; the voltage collected by the voltage collector AD2 is U2-U D2A -R 2A *I 2a ; Among them, R 2A is the resistance value of R2A, I 2a is the current flowing through; the state of the second solenoid valve is the solenoid valve short-circuited to the power supply.

[0022] Preferably, the voltage collected by the voltage collector AD1 is:

[0023] U 二极管 +(U1-2*U 二极管 )*R 电磁阀 / (R 1A +R 电磁阀 ); then the state of the first solenoid valve is the solenoid valve mixed state;

[0024] The voltage collected by voltage collector AD2 is:

[0025] U 二极管 +(U2-2*U 二极管 )*R 电磁阀 / (R 2A +R电磁阀 );The state of the second solenoid valve is the state of mixed installation of solenoid valves.

[0026] To solve the above technical problems, the present invention also provides a device for diagnosing faults of solenoid valves in an electronically controlled APU of a commercial vehicle, which is a device implemented by the above-mentioned method for diagnosing faults of solenoid valves in an electronically controlled APU of a commercial vehicle.

[0027] Due to the adoption of the above technical solutions, the present invention has remarkable technical effects:

[0028] The present invention can diagnose faults of solenoid valves in the electronically controlled system of an automotive intelligent chassis without driving the solenoid valves. Only 1 port resource is required for diagnosing each solenoid valve, and its diagnostic method is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic circuit diagram of the present invention.

[0030] Figure 2 is a diagnostic circuit diagram of the unloading solenoid valve of the present invention.

[0031] Figure 3 is a characteristic curve of the forward voltage drop and forward current of the diode 1N4007G of the present invention at 25°C.

[0032] Figure 4 is an equivalent circuit diagram of the open-circuit state of the solenoid valve of the present invention.

[0033] Figure 5 is an equivalent circuit diagram of the solenoid valve to the power supply circuit state of the present invention.

[0034] Figure 6 is a logic control flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0036] Embodiment 1

[0037] A control circuit of an electronically controlled system of an automotive intelligent chassis, which includes a first fault diagnosis circuit and a second fault diagnosis circuit. Both the first fault diagnosis circuit and the second fault diagnosis circuit include a voltage collector, a voltage dividing circuit and a protection circuit; the protection circuit is used to protect the fault diagnosis circuit, the voltage dividing circuit is used to divide the voltage output by the solenoid valve, and the voltage collector is used to collect the divided voltage; the method for diagnosing faults of solenoid valves in an electronically controlled APU of a commercial vehicle includes:

[0038] Collect the voltage of the solenoid valve in real time through the voltage collector; determine the state of the solenoid valve based on the collected voltage of the solenoid valve.

[0039] The states of the solenoid valves include the solenoid valve short - circuited to ground state, the solenoid valve mis - assembled state, the solenoid valve normal state, the solenoid valve open - circuit state, and the solenoid valve short - circuited to the power supply state.

[0040] The first fault diagnosis circuit includes diode D1A, resistor R1A, diode D1B, resistor R1B, and voltage collector AD1; the anode of diode D1A is connected to input voltage U1; the cathode of diode D1A is connected to voltage collector AD1 and one end of resistor R1A, the other end of resistor R1A is connected to the anode of diode D1B, the cathode of diode D1B is connected to resistor R1B and the solenoid valve output terminal OUT1, and the other end of resistor R1B is grounded; the second fault diagnosis circuit includes diode D2A, resistor R2A, diode D2B, resistor R2B, and voltage collector AD2; the anode of diode D2A is connected to input voltage U2; the cathode of diode D2A is connected to voltage collector AD2 and one end of resistor R2A, the other end of resistor R2A is connected to the anode of diode D2B, the cathode of diode D2B is connected to resistor R2B and the solenoid valve output terminal OUT2, and the other end of resistor R2B is grounded.

[0041] When resistor R1B is much larger than the resistance of the first solenoid valve, the voltage collected by voltage collector AD1 is 0.5U1, and the state of the first solenoid valve is the solenoid valve normal state;

[0042] When resistor R2B is much larger than the resistance of the second solenoid valve, the voltage collected by voltage collector AD2 is 0.5U2, and the state of the second solenoid valve is the solenoid valve normal state.

[0043] When the voltage collected by voltage collector AD1 is the voltage drop at the D1B terminal, the state of the first solenoid valve is the solenoid valve short - circuited to ground state; when the voltage collected by voltage collector AD2 is the voltage drop at the D2B terminal, the state of the second solenoid valve is the solenoid valve short - circuited to ground state.

[0044] The voltage collected by voltage collector AD1 is U D1B +R 1B *I 1b ; where R 1B is the resistance value of R1B, and I 1b is the flowing current; then the state of the first solenoid valve is the solenoid valve open - circuit state; the voltage collected by voltage collector AD2 is U D2B +R 2B *I 2b ; where R 2B is the resistance value of R2B, and I 2bLet I be the current flowing through; then the state of the second solenoid valve is the open state of the solenoid valve.

[0045] The voltage collected by the voltage collector AD1 is U1 - U D1A -R 1A *I 1a ; where R 1A is the resistance value of R1A, and I 1a is the current flowing through; then the state of the first solenoid valve is the short - circuit state of the solenoid valve to the power supply; the voltage collected by the voltage collector AD2 is U2 - U D2A -R 2A *I 2a ; where R 2A is the resistance value of R2A, and I 2a is the current flowing through; then the state of the second solenoid valve is the short - circuit state of the solenoid valve to the power supply.

[0046] The voltage collected by the voltage collector AD1 is:

[0047] U 二极管 +(U1 - 2*U 二极管 )*R 电磁阀 / (R 1A +R 电磁阀 ); then the state of the first solenoid valve is the mixed - installation state of the solenoid valve;

[0048] The voltage collected by the voltage collector AD2 is:

[0049] U 二极管 +(U2 - 2*U 二极管 )*R 电磁阀 / (R 2A +R 电磁阀 ); then the state of the second solenoid valve is the mixed - installation state of the solenoid valve.

[0050] Embodiment 2

[0051] Based on Embodiment 1, this embodiment is a device for diagnosing faults of solenoid valves of a commercial vehicle's electronically controlled APU, which is a device implemented by the above - mentioned method for diagnosing faults of solenoid valves of a commercial vehicle's electronically controlled APU.

[0052] Embodiment 3

[0053] Based on Embodiment 1, Figure 1Among them, D1A is a voltage-dividing diode, and its main function is to divide voltage. Without this diode, the two fault states of the solenoid valve open circuit and short circuit to the power supply cannot be distinguished by voltage. The function of R1A is mainly to divide voltage, and a resistor with a resistance value close to that of the solenoid valve is selected during the design of this resistor. D1B is a reverse cutoff diode, and its main function is to prevent the 24V voltage from directly acting on the pin of the MCU and burning out the MCU. At the same time, it also has the function of dividing voltage. The function of R1B is mainly to divide voltage. Without this resistor, the two fault states of the solenoid valve open circuit and short circuit to the power supply cannot be distinguished by voltage, and a loop to the ground is established when the solenoid valve is open. U9 is a high-side switch used to drive the solenoid valve, but it does not participate in the diagnosis of the solenoid valve.

[0054] For the solenoid valve used in the electric control APU, sufficient power must be available to drive it. For a 24V solenoid valve with a resistance of approximately 80Ω, a voltage of ≥16V must be directly applied to the solenoid valve to drive it. For a 12V solenoid valve with a resistance of approximately 20Ω, a voltage of ≥8V must be directly applied to the solenoid valve to drive the solenoid valve to control the air circuit.

[0055] The commercial electric control APU system is a 24V system, and the diagnostic circuit of the unloading solenoid valve is used for illustration.

[0056] Figure 2 Among them, the resistance R1A is taken as 80Ω, the resistance R1B is taken as 20KΩ, and both D1A and D2A use diodes of model 1N4007G. The voltage of the working power supply of the MCU is 5V. The real-time voltage value collected by the AD acquisition port AD1 is represented by the symbol Va.

[0057] In the normal state of the solenoid valve: The resistance value of R1B > 200 times the resistance of the unloading solenoid valve. When calculating the parallel resistance of R1B and the unloading solenoid valve, it can be ignored. In this way, the circuits from AD1 to +5V and from AD1 to the ground are symmetric up and down, and the voltage is equally divided. Obviously, Va≈2.5V.

[0058] The state of the solenoid valve short circuit to the ground means that the OUT1 port is short circuited to the ground. After the short circuit, the voltage of AD1 is the voltage drop of D1B. Figure 3 is the characteristic curve of the forward voltage drop and forward current of the diode 1N4007G at 25°C (from the data sheet of 1N4007G). When estimating the current Ia passing through D1B, the diode voltage drop is calculated as 0.7V, and Ia≈(5 - 0.7 - 0.7) / 80 = 0.045A. From Figure 3As can be seen in the figure, the diode voltage drop is approximately 0.7V at 0.045A. The above calculation is for reference only. In actual applications, the Va range is confirmed through testing. Testing typically involves taking three to six samples and testing them in a temperature chamber at the electronically controlled APU's operating temperature (-40°C to +85°C). The voltage average is then calculated and the voltage range estimated. When the solenoid valve is short-circuited to ground, Va is approximately 0.7V.

[0059] The above calculations are for reference only. In actual applications, the Va range is confirmed through testing. Testing typically involves taking three to six samples and testing them in a temperature chamber at the electronically controlled APU's operating temperature (-40°C to +85°C). The voltage average is then calculated and the estimated voltage range is estimated. When the solenoid valve is short-circuited to ground, Va ≈ 0.8V.

[0060] Figure 4 The solenoid valve is open or short circuited: The solenoid valve is open or short circuited when the connection between the OUT1 port and the solenoid valve is disconnected. The current Ia passing through D1B is at the uA level and cannot be Figure 3 Estimate the D1A voltage drop. In practical applications, the Va range is confirmed through testing. Testing typically involves taking three to six samples and recording them in a temperature chamber at the electronically controlled APU's operating temperature (-40°C to +85°C). The average voltage is then calculated and the estimated voltage range is estimated. When the solenoid valve is short-circuited to the power supply, Va is approximately 4.50V.

[0061] Figure 5 The solenoid valve is in the short-circuit state to the power supply: The solenoid valve is in the short-circuit state to the power supply when the OUT1 port is short-circuited to the system power supply. When the power supply is short-circuited, the negative voltage of the diode D1B is greater than the positive voltage, the diode D1B is reversely cut off, the equivalent resistance is MΩ level, and the current Ia passing through D1B is nA level, which cannot be Figure 3 Estimate the D1A voltage drop. In practical applications, the Va range is confirmed through testing. Testing typically involves taking three to six samples and recording them in a temperature chamber at the electronically controlled APU's operating temperature (-40°C to +85°C). The average voltage is then calculated and the voltage range estimated. When the solenoid valve is short-circuited to the power supply, Va is approximately 4.85V.

[0062] The solenoid valve replacement state means that the 80Ω 24V solenoid valve is installed with a 20Ω 12V solenoid valve. The resistance of R1B is greater than 200 times the resistance of the unloading solenoid valve. It can be ignored when calculating the parallel resistance of R1B and the unloading solenoid valve. Figure 3 This is the characteristic curve of the forward voltage drop and forward current of the diode 1N4007G at 25°C (from the 1N4007G data sheet). When estimating the current Ia through D1B, the diode voltage drop is calculated as 0.7V, Ia≈(5-0.7-0.7) / (80+20)=0.036A, from Figure 3It can be seen that when the current is 0.036A, the diode voltage drop is approximately 0.7V. Va ≈ 0.7 + (5 - 0.7 - 0.7) * 20 / (80 + 20) = 1.42V.

[0063] There is the following control logic:

[0064] Table 1 Solenoid Valve Control Logic Table

[0065] Unloading solenoid valve status Va Control logic Normal state 2.50V 2.35V ≤ Va ≤ 2.65V, the unloading solenoid valve is in the normal state Ground short circuit 0.7V 0.55V ≤ Va ≤ 0.85V, the unloading solenoid valve is in the ground short circuit state Open circuit 4.50V 4.40V ≤ Va ≤ 4.60V, the unloading solenoid valve is in the open circuit state Power short circuit 4.85V 4.70V ≤ Va ≤ 4.95V, the unloading solenoid valve is in the power short circuit state Mixed state 1.42V 1.22V ≤ Va ≤ 1.62V, the unloading solenoid valve is in the mixed state

[0066] In Figure 6 when the solenoid valve is in the normal state, the collected voltage range is 2.35V ≤ Va ≤ 2.65V; when the unloading solenoid valve is short-circuited to the ground, the collected voltage range is 0.55V ≤ Va ≤ 0.85V; when the unloading solenoid valve is in the open state, the collected voltage range is 4.40V ≤ Va ≤ 4.60V; when the unloading solenoid valve is short-circuited to the power supply, the collected voltage range is 4.70V ≤ Va ≤ 4.95V; when the unloading solenoid valve is in the mixed state, the collected voltage range is 1.22V ≤ Va ≤ 1.62V.

Claims

1. A control circuit for an electronic control system of an intelligent automotive chassis, characterized in that, It includes a first fault diagnosis circuit and a second fault diagnosis circuit. Both the first fault diagnosis circuit and the second fault diagnosis circuit include a voltage collector, a voltage dividing circuit and a protection circuit. The protection circuit is used to protect the fault diagnosis circuit. The voltage dividing circuit is used to divide the voltage output by the solenoid valve. The voltage collector is used to collect the divided voltage. The voltage of the solenoid valve is collected in real time by the voltage collector. The state of the solenoid valve is determined based on the collected voltage of the solenoid valve.

2. The control circuit of an intelligent chassis electronic control system for an automobile according to claim 1, characterized in that, The states of the solenoid valve include the solenoid valve short - circuit to ground state, the solenoid valve misassembly state, the solenoid valve normal state, the solenoid valve open - circuit state and the solenoid valve short - circuit to power supply state.

3. The control circuit of an automotive intelligent chassis electronic control system according to claim 2, characterized in that, The first fault diagnosis circuit includes diode D1A, resistor R1A, diode D1B, resistor R1B and voltage collector AD1. The anode of diode D1A is connected to input voltage U1. The cathode of diode D1A is connected to one end of resistor R1A. The other end of resistor R1A is connected to voltage collector AD1 and the anode of diode D1B. The cathode of diode D1B is connected to resistor R1B and the solenoid valve output terminal OUT1. The other end of resistor R1B is grounded. The second fault diagnosis circuit includes diode D2A, resistor R2A, diode D2B, resistor R2B and voltage collector AD2. The anode of diode D2A is connected to input voltage U2. The cathode of diode D2A is connected to one end of resistor R2A. The other end of resistor R2A is connected to voltage collector AD2 and the anode of diode D2B. The cathode of diode D2B is connected to resistor R2B and the solenoid valve output terminal OUT2. The other end of resistor R2B is grounded.

4. The control circuit of an automotive intelligent chassis electronic control system according to claim 3, characterized in that, When resistor R1B is much larger than the resistance of the first solenoid valve, the voltage collected by voltage collector AD1 is 0.5U1, and the state of the first solenoid valve is the solenoid valve normal state. When resistor R2B is much larger than the resistance of the second solenoid valve, the voltage collected by voltage collector AD2 is 0.5U2, and the state of the second solenoid valve is the solenoid valve normal state.

5. The control circuit of an intelligent chassis electronic control system for an automobile according to claim 3, characterized in that, When the voltage collected by voltage collector AD1 is the voltage drop at the diode D1B end, the state of the first solenoid valve is the solenoid valve short - circuit to ground state. When the voltage collected by voltage collector AD2 is the voltage drop at the diode D2B end, the state of the second solenoid valve is the solenoid valve short - circuit to ground state.

6. The control circuit of an automotive intelligent chassis electronic control system according to claim 3, characterized in that, The voltage collected by the voltage collector AD1 is U D1B +R 1B *I 1b ; where, R 1B is the resistance value of R1B, and I 1b is the current flowing through; then the state of the first solenoid valve is the solenoid valve open state; the voltage collected by the voltage collector AD2 is U D2B +R 2B *I 2b ; where, R 2B is the resistance value of R2B, and I 2b is the current flowing through; then the state of the second solenoid valve is the solenoid valve open state.

7. The control circuit of an automotive intelligent chassis electronic control system according to claim 3, characterized in that, The voltage collected by the voltage collector AD1 is U1 - U D1A -R 1A *I 1a ; Among them, R 1A is the resistance value of R1A, and I 1a is the current flowing through; then the state of the first solenoid valve is the state where the solenoid valve is short-circuited to the power supply; the voltage collected by the voltage collector AD2 is U2 - U D2A -R 2A *I 2a ; among them, R 2A is the resistance value of R2A, and I 2a is the current flowing through; then the state of the second solenoid valve is the state where the solenoid valve is short-circuited to the power supply.

8. The control circuit of an intelligent chassis electronic control system for an automobile according to claim 3, characterized in that, The voltage collected by voltage collector AD1 is: U 二极管 +(U1 - 2 * U 二极管 ) * R 电磁阀 / (R 1A + R 电磁阀 );Then the state of the first solenoid valve is the solenoid valve mixed - assembly state; The voltage collected by voltage collector AD2 is: U 二极管 +(U2 - 2 * U 二极管 ) * R 电磁阀 / (R 2A + R 电磁阀 );The state of the second solenoid valve is the state of mixed installation of solenoid valves.

9. An intelligent chassis electronic control system for an automobile, characterized in that, It includes the control circuit of an automotive intelligent chassis electronic control system according to any one of claims 1 - 8.

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