CN109406906A

CN109406906A - The detecting tool and detection method of SCR system diagnostic device

Info

Publication number: CN109406906A
Application number: CN201811494246.3A
Authority: CN
Inventors: 蔡继业; 郝俊杰; 王伟
Original assignee: Shanghai Xingrong Automobile Technology Co Ltd
Current assignee: Shanghai Xingrong Automobile Technology Co Ltd
Priority date: 2018-12-07
Filing date: 2018-12-07
Publication date: 2019-03-01

Abstract

A kind of detecting tool of SCR system diagnostic device, including the adjustable output module of voltage as load blocks, resistance adjustable module, short block and power module, first CAN communication module, first interface and MCU controller, the adjustable output module of voltage, resistance adjustable module, short block, power module, first CAN communication module and first interface are connect with the MCU controller, and the adjustable output module of voltage, resistance adjustable module, short block, power module and the first CAN communication module are connect with the first interface, the first interface has multiple pins of corresponding each load blocks, form the sense channel of corresponding each load blocks.The present invention can high-efficient automatic detection, save detection time and human input, can batch detection, and detection accuracy is high, covers various operating conditions, avoids erroneous judgement caused by artificial origin, eliminates influence of the initial failure component to equipment.

Description

The detecting tool and detection method of SCR system diagnostic device

Technical field

The present invention relates to the detections of the detection technique field of SCR system diagnostic device more particularly to SCR system diagnostic device Tooling and detection method.

Background technique

It is more and more using diesel engine as power as national legislation is to require continuous of automotive emission plus tight Vehicle on require install additional SCR system, by accurate quantification spray high pressure urea solution into exhaust pipe, in tail gas NOx reacts, and produces N2 and H2O, cleaning of off-gas.High pressure urea is by urea pump to generation after urea pressurization.

In actual operation, because urea quality is poor, the operating condition that works and bad environments, driver, which maintains, realizes low, urea The a variety of causes such as itself existing defects are pumped, urea pump is caused to be easily damaged, after urea pump damage, vehicle quotes OBD failure, and swashs Performance living to vehicle limits, and urges driver's on-call maintenance.Maintenance urea pump needs to use SCR system diagnostic device, SCR system Diagnostic device is the diagnostic device for diagnosing urea pump and core sensor exploitation in SCR system, is used to Measuring error urea pump.

Urea pump has various failure modes in practice, and SCR system diagnostic device (hereinafter referred to as device) must be able to Enough detect the various failures of urea pump, and under various failures, device can work normally unaffected.The original intention of device is Diagnosis SCR system will lead to the result mistake of detection, influence to judge if there are failures for itself, it is therefore necessary to guarantee device certainly The function of body is normal.

The method detected at present for the function of device has following two:

1, before and after PCB patch, the voltage of each test point on pcb board is detected, by the tooling of customization to judge the electricity Whether road is normal；

2, after device fills, with the intact Devices to test with dysfunction of the device diagnostic function, pass through test and tie Whether the functionality that fruit analyzes the device is intact.

The shortcomings that both methods, is as follows:

1, by traditional tooling test, it can only ensure the on-off of circuit, function difference caused by the difference of component itself It can not detect；

2, by with this mode of device to test part to be measured, can the feedback test time point equipment function integrity.But It is this detection method:

1) inefficiency can not be tested in high volume, can not quick copy.

2) subjective judgement of tester is relied on, it is not objective enough.

3) test it is insufficient, can not various operating conditions in cladding system work, test result do not represent truth.

Summary of the invention

Based on this, in view of the above technical problems, detecting tool and the detection side of a kind of SCR system diagnostic device are provided Method.

In order to solve the above technical problems, the present invention adopts the following technical scheme:

A kind of detecting tool of SCR system diagnostic device, including the adjustable output module of voltage, the resistance as load blocks Adjustable module, short block and power module, the first CAN communication module, first interface and MCU controller, the voltage can Adjust output module, resistance adjustable module, short block, power module, the first CAN communication module and first interface with it is described The connection of MCU controller, and the adjustable output module of the voltage, resistance adjustable module, short block, power module and first CAN communication module is connect with the first interface, and the first interface has multiple pins of corresponding each load blocks, is formed The sense channel of corresponding each load blocks.

The pin of the first interface is 44.

The invention further relates to a kind of detection methods of SCR system diagnostic device, comprising:

The first interface that will test tooling is connect with the second interface of SCR system diagnostic device, and the SCR system is diagnosed Device is connect with computer, the detecting tool include the adjustable output module of voltage as load blocks, resistance adjustable module, Short block and power module, the first CAN communication module, first interface and MCU controller, the adjustable output mould of voltage Block, resistance adjustable module, short block, power module, the first CAN communication module and first interface are controlled with the MCU Device connection, and the adjustable output module of the voltage, resistance adjustable module, short block, power module and the first CAN communication mould Block is connect with the first interface, and the first interface has multiple pins of corresponding each load blocks, is formed corresponding each negative Carry the sense channel of module；

The SCR system diagnostic device sends detection information to the detecting tool by second interface；

The MCU controller of the detecting tool receives the detection from first interface by the first CAN communication module Information switches to corresponding sense channel according to the detection information, and sets to corresponding load blocks；

The SCR system diagnostic device sets detection parameters, is acquired under the detection parameters by corresponding diagnostic module The detection data of present load module, and the detection parameters, detection data and detection information are sent to computer；

The computer searches corresponding permissible value range according to the detection parameters and detection information from database, The detection data and the permissible value range are compared, judge whether Current Diagnostic functions of modules is normal.

The first interface and the pin of second interface are 44.

The detection information is a data frame, and the data frame includes frame I D and 7 bytes, 7 bytes point Not Biao Shi:

First character section is frame head；

Second byte is byte length；

Third byte is driving type；

4th byte is the diagnosis channel number of SCR system diagnostic device；

5th byte is load model；

6th byte be verification and；

7th byte is postamble.

The invention has the following advantages that

1, high-efficient automatic detects, and saves detection time and human input, can batch detection, and detection accuracy is high, Cover various operating conditions；

2, erroneous judgement caused by artificial origin is avoided；

3, influence of the initial failure component to equipment is eliminated.

Detailed description of the invention

The following describes the present invention in detail with reference to the accompanying drawings and specific embodiments:

Fig. 1 is the structural diagram of the present invention.

Specific embodiment

As shown in Figure 1, a kind of detecting tool 10 of SCR system diagnostic device, adjustable including the voltage as load blocks Output module 11, resistance adjustable module 12, short block 13 and power module 14, the first CAN communication module 15, first interface 16 And MCU controller 17.

Voltage is adjustable output module 11, resistance adjustable module 12, short block 13, power module 14, the first CAN communication mould Block 15 and first interface 16 are connect with MCU controller 17, and the adjustable output module 11 of voltage, resistance adjustable module 12, short Road module 13, power module 14 and the first CAN communication module 15 are connect with first interface 16, and first interface 16, which has, to be corresponded to Multiple pins of each load blocks form the sense channel of corresponding each load blocks.

Wherein, the adjustable output module 11 of voltage exports operating condition for analog voltage, and resistance adjustable module 12 is for simulating electricity Resistance output operating condition, short block 13 export operating condition for simulated power for simulating Short-circuit Working Condition, power module 14.

It is pointed out that the adjustable output module 11 of voltage, resistance adjustable module 12, short block 13 and power module 14 be common module, wherein voltage is adjustable, and output module 11 switches different electric resistance partial pressure realizations by relay, and resistance is 24 1k ohm of resistance, precision 1v adjustable by the achievable 0-24v of series connection partial pressure；Resistance adjustable module 12 passes through relay Switch different resistance to realize, resistance be 10 ohm, 200 ohm, 1000 ohm, 10000 ohm, 100000 ohm and 300000 ohm；Short block 13 can be understood as the load that resistance is 0, and details are not described herein again；Power module 14 passes through relay Device switches different power resistors and realizes, power resistor specification: 50W2R, 50W10R and 50W100R.

It is as follows that detection process is carried out to SCR system diagnostic device 20 using detecting tool 10 of the present invention:

1, the first interface 16 that will test tooling 10 is connect with the second interface 21 of SCR system diagnostic device 20, by SCR system System diagnostic device 20 is connect with computer 3.

Wherein, SCR system diagnostic device 20 has multiple diagnostic modules, referring to table 1.

Diagnostic module	Quantity	Remarks
			The low control module of PWM	6	Including current acquisition
PWM high control module	2	Including current acquisition
			DCM direct current generator module	3
Voltage acquisition module	6	Acquisition range 0-32V
			Electrical resistance collection module	4	0-300 kilohms
CAN communication module	1	250kbs

Table 1

In the present embodiment, first interface 16 and the pin of second interface 21 are 44, and the definition of pin is referring to table 2。

Definition

Remarks

Definition

Remarks

Definition

Remarks

1

Vout1

Power supply output-positive .12/24Vdc

16

DC1

Power input 1 (13~29VDC)

31

0C1-

Power input 1

2

Vout+

Power supply exports a positive .12/24Vdc

17

DC1+

Power input 1 (13~29VDC)

32

0C1-

Power input 1

3

PWM1

It is low effectively that PWM exports (NPN)

18

DCI+

Power input 1 (13~29VDC)

33

DC1-

Power input 1

4

PWM2

It is low effectively that PWM exports (NPN)

19

34

Gnd

Power supply output-ground

5

DCM1-

Direct current generator A

20

PWM3

It is low effectively that PWM exports (NPN)

35

Gnd

Power supply output-ground

6

DCM1+

21

PWM4

It is low effectively that PWM exports (NPN)

36

Gnd

Power supply output-ground

7

DCM2-

Direct current generator B

22

PWM5

It is low effectively that PWM exports (NPN)

37

Gnd

Power supply output-ground

8

DCM2+

23

PWM6

It is low effectively that PWM exports (NPN)

38

Gnd

Power supply output ground

9

DCM3-

Direct current generator C

24

PWM7

It is low effectively that PWM exports (NPN)

39

5Vdc

Power supply output-just, 5Vde

10

DCM3+

25

PWM6

It is low effectively that PWM exports (NPN)

40

5Vde

Power supply output-just, 5Vde

11

Ai1

Voltage signal inputs 1 (0-32V)

26

DO1

Small function string PWM, it is low effective

41

Gnd

12

Ri2

Resistance signal input 2

27

Ai2

Voltage signal inputs 2 (0~32V)

42

Ri1

Resistance signal input 1

13

Rb4

Resistance signal input 4

28

Rt3

Resistance signal input 3

43

CAN2L

14

Ai4

Voltage signal inputs 4 (0~32V)

29

Ai3

Voltage signal inputs 3 (0~32V)

44

CAN2H

15

Ai6

Voltage signal inputs 6 (0~32V)

30

Ai5

Voltage signal inputs 5 (0-32V)

Table 2

2, after starting detection, SCR system diagnostic device 20 sends detection information to detecting tool 10 by second interface 21.

3, the MCU controller 17 of detecting tool 10 receives above-mentioned inspection from first interface 16 by the first CAN communication module 15 Measurement information switches to corresponding sense channel according to the detection information, and sets to corresponding load blocks.

The voltage acquisition module of SCR system diagnostic device 20 is detected, different output is generally adjusted by rotating potentiometer Voltage is compared by the voltage signal of the collected voltage signal of artificial judgment means and reality output.This method is not Can accurately judge that whether voltage and the requirements of offer are consistent；And when switching output voltage, need operator manual It adjusts, time-consuming and laborious inefficiency, the present invention need to only switch to the adjustable output module 11 of voltage and can detect as load.

The electrical resistance collection module of SCR system diagnostic device 20 is detected, it is general that test resistance is adjusted by slide rheostat, lead to It crosses the collected resistance of artificial judgment means and reality output resistance compares.This method cannot accurately judge that offer Whether resistance is consistent with requirements, and when switching output resistance, needs operator to manually adjust, time-consuming and laborious low efficiency Under, the present invention need to only switch to resistance adjustable module 12 and can detect as load.

In practical applications, urea pump can have the risk of short circuit, work of the SCR system diagnostic device 20 in urea pump short circuit Under condition, it should play and automatically cut off output, the function of protective device itself and urea pump avoids secondary damage.Therefore in detection ring Section needs to simulate Short-circuit Working Condition, in the case where power supply, carries out short-circuit test using Du Pont's line manually.This test method is not only It is time-consuming, and there are certain risk, the present invention need to only switch to short block 13 and can detect.

The design power of SCR system diagnostic device 20 is larger, and projected life is longer, needs to carry out aging to each diagnostic module It tests, prevents from influencing device normal function because of component initial failure, it can be using the side continued working, stepped increase loads Formula successively switches to each load blocks, carries out burn-in test respectively to each diagnostic module, to exclude the morning of some electronic devices Phase failure leads to equipment failure.

In addition, PWM high control module, the low control module of PWM or the DCM direct current generator mould of detection SCR system diagnostic device 20 When block, the present invention need to only switch to power module 14 and can detect.

4, SCR system diagnostic device 20 sets detection parameters, is acquired under detection parameters by corresponding diagnostic module current The detection data of load blocks, and will test parameter, detection data and detection information and be sent to computer 3.

Wherein, detection parameters refer to the load of SCR system diagnostic device 20.

In the present embodiment, detection information is a data frame, and data frame includes frame ID and 7 bytes, 7 bytes point Not Biao Shi:

First character section is frame head；

Second byte is byte length；

Third byte is driving type；

4th byte is the diagnosis channel number of SCR system diagnostic device；

5th byte is load, i.e., can find corresponding load blocks and its setting value by the 5th byte；

6th byte be verification and；

7th byte is postamble.

Three, four, five byte specific definitions are referring to table 3, and when such as the 5th byte is 0x01, corresponding load blocks are power electricity It hinders (power module 14), setting value is 2 Ω.

Drive type	Drive title	Channel number	Tunnel name	Load	Load details
						0x01	Direct current generator	0x01	DCM1	0x01	2Ω
0x01	Direct current generator	0x02	DCM2	0x02	10Ω
						0x01	Direct current generator	0x03	DCM3	0x03	100Ω
0x02	P load	0x01	P1	0x01	2Ω
						0x02	P load	0x02	P2	0x02	10Ω
0x02	P load			0x03	100Ω
						0x03	N load	0x01	N1	0x01	2Ω
0x03	N load	0x02	N2	0x02	10Ω
						0x03	N load	0x03	N3	0x03	100Ω
0x03	N load	0x04	N4
						0x03	N load	0x05	N5
0x03	N load	0x06	N6
						0x04	Resistance detection	0x01	RT1	0x04	10Ω
0x04	Resistance detection	0x02	RT2	0x05	200Ω
						0x04	Resistance detection	0x03	RT3	0x06	1000Ω
0x04	Resistance detection	0x04	RT4	0x07	10000Ω
						0x04	Resistance detection			0x08	100000Ω
0x04	Resistance detection			0x09	300000Ω
						0x05	Voltage detecting	0x01	V1	0x0a	0.5V
0x06	Voltage detecting	0x02	V2	0x0b	5V
						0x05	Voltage detecting	0x03	V3	0x0c	12V
0x05	Voltage detecting	0x04	V4	0x0d	32V
						0x05	Voltage detecting	0x05	V5
0x05	Voltage detecting	0x06	V6
						0x00	Shutdown command

Table 3

5, computer 3 searches corresponding permissible value range according to detection parameters and detection information from database, will examine Measured data is compared with permissible value range, judges whether Current Diagnostic functions of modules is normal.

Permissible value range corresponding with detection information is stored in database referring to table 4.

Drive end	Diagnose channel	Load	Load	Setting value	Allowed band
						01	01	50%	01	6000	± 5%
01	01	100%	01	12000	± 5%
						01	01	10%	01	1200	± 5%
01	01	20%	01	2400	± 5%
						……	……	……	……	……	……

Table 4

Below by taking the 18FF100A data frame that frame ID is as an example: 04 01 01 01 01 7E of 18FF100A 7E.

After detecting tool 10 receives the data frame, it is switched to power module 14, load set is 2 ohm, SCR system diagnosis 20 assumed load of device is 50%, acquires the detection data of power module 14 under 50% load by DCM1 direct current generator module, The collected average current of DCM1 direct current generator module be 5800ma, and will test parameter (50% load), detection data and Detection information is sent to computer 3.

Computer 3 searches corresponding permissible value range (referring to table 4) from database: permission electric current is 6000 ± 300ma, Measured value is in range, therefore this test is normal.

But those of ordinary skill in the art it should be appreciated that more than embodiment be intended merely to illustrate this Invention, and be not used as limitation of the invention, as long as in spirit of the invention, to embodiment described above Variation, modification will all fall within the scope of claims of the present invention.

Claims

1. a kind of detecting tool of SCR system diagnostic device, which is characterized in that including the adjustable output of voltage as load blocks Module, resistance adjustable module, short block and power module, the first CAN communication module, first interface and MCU controller, institute State the adjustable output module of voltage, resistance adjustable module, short block, power module, the first CAN communication module and first interface Connect with the MCU controller, and the adjustable output module of the voltage, resistance adjustable module, short block, power module with And first CAN communication module connect with the first interface, there are the first interface corresponding each the multiple of load blocks to draw Foot forms the sense channel of corresponding each load blocks.

2. a kind of detecting tool of SCR system diagnostic device according to claim 1, which is characterized in that described first connects The pin of mouth is 44.

3. a kind of detection method of SCR system diagnostic device characterized by comprising

The first interface that will test tooling is connect with the second interface of SCR system diagnostic device, by the SCR system diagnostic device It is connect with computer, the detecting tool includes the adjustable output module of voltage, the resistance adjustable module, short circuit as load blocks Module and power module, the first CAN communication module, first interface and MCU controller, the voltage is adjustable output module, electricity Adjustable module, short block, power module, the first CAN communication module and first interface is hindered to connect with the MCU controller It connects, and the adjustable output module of the voltage, resistance adjustable module, short block, power module and the first CAN communication module are equal It is connect with the first interface, the first interface has multiple pins of corresponding each load blocks, forms corresponding each load mould The sense channel of block；

The MCU controller of the detecting tool receives the detection information from first interface by the first CAN communication module, Corresponding sense channel is switched to according to the detection information, and corresponding load blocks are set；

The SCR system diagnostic device sets detection parameters, is acquired under the detection parameters by corresponding diagnostic module current The detection data of load blocks, and the detection parameters, detection data and detection information are sent to computer；

The computer searches corresponding permissible value range according to the detection parameters and detection information from database, by institute It states detection data to compare with the permissible value range, judges whether Current Diagnostic functions of modules is normal.

4. a kind of detection method of SCR system diagnostic device according to claim 3, which is characterized in that described first connects Mouth and the pin of second interface are 44.

5. a kind of detection method of SCR system diagnostic device according to claim 3 or 4, which is characterized in that the detection Information is a data frame, and the data frame includes frame ID and 7 bytes, and 7 bytes respectively indicate:

First character section is frame head；

Second byte is byte length；

Third byte is driving type；

4th byte is the diagnosis channel number of SCR system diagnostic device；

5th byte is load model；

6th byte be verification and；

7th byte is postamble.