Diesel engine exhaust aftertreatment system urea pump drive motor current closed-loop control chip

Abstract

This invention discloses a closed-loop control chip for the current of a urea pump drive motor in a diesel engine exhaust aftertreatment system. The chip includes a control bus and a reference module, a monitoring module, a feedback module, and a cache module electrically connected to the control bus. The CPU configures the cache module for reading and writing via the control bus. The reference module provides bias current to the control chip. The monitoring module monitors the transient current of the drive pump motor in real time and stores the transient current data in the cache module in a first state for current data caching. The control bus retrieves the transient current data from the cache module and compares it with the bias current to obtain a current difference. The feedback module is configured to adjust the bias current of the reference module and adjust the operating parameters of the drive pump motor when the current difference exceeds a first threshold. This application achieves signal interconnection between multiple modules through control bus technology, reducing signal attenuation during transmission.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of current control, more particularly, to a urea pump driving motor current closed-loop control chip for a diesel engine exhaust aftertreatment system. BACKGROUND

[0002] According to the current diesel engine exhaust emission regulations, CO / HC caused by incomplete combustion, PM and NOx generated in the combustion process all need to be controlled by an aftertreatment system. The conventional method is to use a diesel oxidation catalyst (DOC) to control the emission of CO / HC and generate NO2 to meet the passive regeneration of a subsequent diesel particulate filter (CSF) and the reaction of a selective reduction catalyst (SCR). Or burn fuel to provide sufficient temperature for the active regeneration of the CSF. The wall-flow CSF with a catalyst coating is used for particle treatment, and the SCR is used for NOx emission. In the regeneration of the trapped particulate matter (PM) in the CSF, passive regeneration with NO2 as the oxidant and active regeneration with O2 as the oxidant are generally used. The DOC is used to generate NO2 for passive regeneration of the CSF or to provide sufficient temperature for active regeneration. The ammonia slip catalyst (ASC) is used to prevent NH3 leakage caused by urea over-injection. During the diesel engine exhaust treatment process, how to accurately control the driving pump motor to control the urea injection amount becomes an urgent technical problem to be solved. SUMMARY

[0003] To solve the above at least one technical problem, the present application provides a urea pump driving motor current closed-loop control chip for a diesel engine exhaust aftertreatment system.

[0004] The first aspect of the present application provides a urea pump driving motor current closed-loop control chip for a diesel engine exhaust aftertreatment system, comprising: a control bus and a reference module, a monitoring module, a feedback module and a cache module electrically connected to the control bus; a CPU reads and writes the cache module through the control bus for configuration;

[0005] The reference module is used to provide a bias current for the control chip;

[0006] The monitoring module is used to monitor the transient current of the driving pump motor in real time, and store the transient current data to the cache module in the first state for current data caching;

[0007] The control bus is used to mobilize the transient current data in the cache module, compare the transient current data with the bias current, and obtain a current difference,

[0008] The feedback module is configured to adjust the bias current of the reference module when the current difference is greater than a first threshold, and adjust the operating parameters of the driving pump motor.

[0009] In a preferred embodiment of the present application, the cache module is internally provided with a plurality of program areas, the cache module encodes each program area separately, and generates an encoding value and / or a check value corresponding to the program area.

[0010] In a preferred embodiment of the present application, the reference module includes a reference voltage circuit and a reference current circuit, the reference voltage circuit is configured to adjust the voltage input through the VCC pin to the voltage VDD used internally when the chip is powered on.

[0011] The reference current circuit is configured to provide a bias current for controlling the chip.

[0012] In a preferred embodiment of the present application, the reference current circuit includes a Schmitt trigger control circuit and a constant current source circuit, the Schmitt trigger control circuit and the constant current source circuit are electrically connected, and the Schmitt trigger control circuit controls the constant current source circuit to output a bias current signal with stable frequency.

[0013] In a preferred embodiment of the present application, the current closed-loop control chip further includes a driving module, the driving module is electrically connected with the control bus, and the driving module is used to control the operation of the driving pump motor.

[0014] In a preferred embodiment of the present application, the current closed-loop control chip further includes a protection circuit module, the protection circuit module is used for state protection during the operation of the chip, and the protection circuit module includes an over-temperature protection unit, an over-current protection unit, and an overload protection unit.

[0015] The over-temperature protection unit is configured to control the current value of the bias current of the reference module through the control bus when the temperature of the chip is higher than a preset temperature.

[0016] The over-current protection unit is configured to cut off the VDD voltage of the chip through the control bus and stop the operation of the chip when the transient current is greater than a second threshold value, thereby protecting the motor.

[0017] The overload protection unit is configured to control the chip to restart through the control circuit when the input voltage of the motor is greater than a preset voltage threshold.

[0018] In a preferred embodiment of the present application, the current closed-loop control chip is internally provided with a slope compensation circuit, the slope compensation circuit is configured to output a slope current and input the slope current to the feedback module, thereby compensating and adjusting the bias current of the reference module and realizing feedback control of the driving pump motor current.

[0019] In a preferred embodiment of the present application, the feedback module includes a positive feedback circuit and a negative feedback circuit, and the positive feedback circuit and the negative feedback circuit can be switched.

[0020] In a preferred embodiment of the present invention, the starting current of the current closed-loop control chip when powered on is 1.65-1.88mA.

[0021] In a preferred embodiment of the present invention, the VDD voltage value of the current closed-loop control chip is 13.8-15.3V when it is powered on.

[0022] Compared with the prior art, the beneficial technical effects obtained by the present invention are as follows:

[0023] This application achieves signal interconnection of multiple modules through control bus technology, reduces signal attenuation during signal transmission, and improves the sensitivity of signal output. In addition, by setting a monitoring module, the transient current of the drive pump motor can be monitored in real time, and current protection or current compensation can be performed to achieve constant current input and improve the safety and flexibility of the drive pump motor during use. Attached Figure Description

[0024] Fig. 1 A schematic diagram of the current closed-loop control chip structure of the urea drive pump motor of the present invention is shown;

[0025] Fig. 2 A block diagram of the protection circuit module structure of the present invention is shown;

[0026] Fig. 3 A block diagram of the basic module structure of the present invention is shown.

[0027] In the diagram, 100 represents the control bus.

[0028] 10. Baseline module; 20. Monitoring module; 30. Feedback module; 40. Cache module; 41. Program area. Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0031] like Figs. 1-3As shown, the first aspect of the present invention provides a closed-loop control chip for the current of a urea pump drive motor in a diesel engine exhaust aftertreatment system, comprising: a control bus 100 and a reference module 10, a monitoring module 20, a feedback module 30, and a cache module 40 electrically connected to the control bus 100; the CPU performs read and write configuration of the cache module 40 through the control bus 100; the reference module 10 is used to provide bias current for the control chip; the monitoring module 20 is used to monitor the transient current of the drive pump motor in real time, and in a first state, the transient current data is stored in the cache module 40 for current data caching;

[0032] The control bus 100 is used to retrieve transient current data from the buffer module 40 and compare the transient current data with the bias current to obtain the current difference.

[0033] The feedback module 30 is configured to adjust the bias current of the reference module 10 and adjust the operating parameters of the drive pump motor when the current difference is greater than the first threshold.

[0034] Thus, the control bus 100 technology provided by this invention enables signal interconnection of multiple modules, reduces signal attenuation during signal transmission, and improves the sensitivity of signal output.

[0035] Specifically, the cache module 40 has multiple program areas 41 inside. The cache module 40 encodes each program area 41 separately and generates an encoded value and / or a check value corresponding to that program area 41.

[0036] In one specific example, the reference module 10 includes a reference voltage circuit and a reference current circuit. The reference voltage circuit is configured to adjust the voltage connected to the VCC pin to the voltage VDD used inside the chip when the chip is powered on. The reference current circuit is configured to provide bias current for controlling the chip.

[0037] The starting current of the current closed-loop control chip is 1.65-1.88mA when it is powered on.

[0038] Preferably, the startup current of the current closed-loop control chip is 1.77mA when it is powered on.

[0039] In addition, the VDD voltage value of the current closed-loop control chip is 13.8-15.3V when powered on.

[0040] Preferably, the VDD voltage value of the current closed-loop control chip is 14.8V when it is powered on.

[0041] In one specific example, the reference current circuit includes a Schmitt trigger control circuit and a constant current source circuit. The Schmitt trigger control circuit is electrically connected to the constant current source circuit, and the constant current source circuit is controlled by the Schmitt trigger control circuit to output a bias current signal with a stable frequency.

[0042] In one specific example, the current closed-loop control chip also includes a drive module electrically connected to the control bus 100, which is used to control the operation of the drive pump motor.

[0043] In one specific example, the current closed-loop control chip also includes a protection circuit module, which is used for state protection during chip operation. The protection circuit module includes an over-temperature protection unit, an over-current protection unit, and an overload protection unit.

[0044] The over-temperature protection unit is configured to control the bias current value of the reference module 10 via the control bus 100 when the chip temperature is higher than the preset temperature.

[0045] The overcurrent protection unit is configured to cut off the chip's VDD voltage via the control bus 100 and stop the chip from running when the transient current exceeds the second threshold, thus protecting the motor.

[0046] The overload protection unit is configured such that when the motor input voltage exceeds a preset voltage threshold, the control bus 100 restarts the chip via the control circuit.

[0047] In another specific example, the current closed-loop control chip has a built-in slope compensation circuit. The slope compensation circuit is configured to output a slope current and input the slope current to the feedback module 30 to compensate and adjust the bias current of the reference module 10, thereby realizing feedback control of the current of the drive pump motor.

[0048] Furthermore, the feedback module 30 includes a positive feedback circuit and a negative feedback circuit, which can be switched.

[0049] In summary, by setting up the monitoring module 20, the transient current of the drive pump motor can be monitored in real time, and current protection or current compensation can be performed to achieve constant current input and improve the safety and flexibility of the drive pump motor during use.

[0050] The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined, integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0051] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units; some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0052] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0053] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0054] Alternatively, if the integrated units of this invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

[0055] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A diesel engine exhaust aftertreatment system urea pump drive motor current closed loop control chip, characterized in that, include: The control bus and a reference module, monitoring module, feedback module and buffer module electrically connected to the control bus; The CPU configures the cache module for reading and writing via the control bus; The reference module is used to control the chip to provide bias current; The monitoring module is used to monitor the transient current of the drive pump motor in real time, and in the first state, the transient current data is stored in the cache module for caching the current data. The control bus is used to access transient current data in the cache module and compare the transient current data with the bias current to obtain the current difference. The feedback module is configured to adjust the bias current of the reference module and adjust the operating parameters of the drive pump motor when the current difference is greater than the first threshold. The cache module has multiple program areas inside. The cache module encodes each program area separately and generates an encoding value and / or check value corresponding to that program area. The reference module includes a reference voltage circuit and a reference current circuit. The reference voltage circuit is configured to adjust the voltage connected to the VCC pin to the voltage VDD used inside the chip when the chip is powered on. The reference current circuit is configured to provide bias current to the control chip; The reference current circuit includes a Schmitt control circuit and a constant current source circuit. The Schmitt control circuit and the constant current source circuit are electrically connected. The Schmitt control circuit controls the constant current source circuit to output a bias current signal with a stable frequency. The current closed-loop control chip has a built-in slope compensation circuit. The slope compensation circuit is configured to output a slope current and input the slope current to the feedback module to compensate and adjust the bias current of the reference module, thereby realizing feedback control of the current of the drive pump motor.

2. The diesel exhaust after-treatment system urea pump drive motor current closed loop control chip of claim 1, wherein, The current closed-loop control chip also includes a drive module, which is electrically connected to the control bus and is used to control the operation of the drive pump motor.

3. The diesel exhaust after-treatment system urea pump drive motor current closed loop control chip of claim 2, wherein, The current closed-loop control chip also includes a protection circuit module, which is used for status protection during chip operation. The protection circuit module includes an over-temperature protection unit, an over-current protection unit, and an overload protection unit. The over-temperature protection unit is configured to control the bias current value of the reference module via the control bus when the chip temperature is higher than the preset temperature. The overcurrent protection unit is configured to cut off the chip's VDD voltage via the control bus and stop the chip from running when the transient current exceeds the second threshold, thereby protecting the motor. The overload protection unit is configured such that when the motor input voltage exceeds a preset voltage threshold, the control bus restarts the chip via the control circuit.

4. The diesel exhaust after-treatment system urea pump drive motor current closed loop control chip of claim 1, wherein, The feedback module includes a positive feedback circuit and a negative feedback circuit, and the positive feedback circuit and the negative feedback circuit can be switched.

5. The diesel exhaust after-treatment system urea pump drive motor current closed loop control chip of claim 1, wherein, The starting current of the current closed-loop control chip is 1.65-1.88mA when powered on.

6. The diesel exhaust after-treatment system urea pump drive motor current closed loop control chip of claim 1, wherein, The current closed-loop control chip has a VDD voltage of 13.8-15.3V when powered on.

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