阅读说明：本技术 一种多路热电偶温度输入信号的分时处理的方法及系统 (Time-sharing processing method and system for temperature input signals of multiple thermocouples ) 是由 宋长营 李铁军 于 2020-06-12 设计创作，主要内容包括：本发明提供一种多路热电偶温度输入信号的分时处理的方法及系统,包括以下工序：步骤S1：定时启动排放温度测试设备,单片机接收记录当前通道的数据；步骤S2：单片机通过GPIO输出信号给多路转换开关,改变热电偶温度测点的通道将当前通道导通,并关闭已经采样完毕的通道；步骤S3：循环上述步骤S1到步骤S2,直至将所有通道的温度记录完成；步骤S4：由于从打开通道到通道工作稳定需要一段时间,而主程序定时器将在下一个间隔时刻开始下一次读取操作,期间的间隔就用于稳定通道工作。本发明通过分时利用前置芯片的工作能力,将多路温度信号通过多路开关转换分时地使用前置采样芯片,实现使用一个芯片将多路温度信号输入单片机的效果,达到降低成本的目标。(The invention provides a time-sharing processing method and a time-sharing processing system for temperature input signals of a plurality of thermocouples, which comprise the following procedures: step S1: starting the discharge temperature testing equipment at fixed time, and receiving and recording data of the current channel by the singlechip; step S2: the single chip microcomputer outputs signals to the multi-path change-over switch through the GPIO, changes a channel of the thermocouple temperature measuring point, conducts the current channel and closes the channel which is sampled completely; step S3: looping the above steps S1 to S2 until the temperature recording of all channels is completed; step S4: since it takes a while from opening the channel until the channel operation is stable, the main program timer will start the next read operation at the next interval, and the interval therebetween is used to stabilize the channel operation. The invention uses the working capacity of the preposed chip in a time-sharing way, converts the multipath temperature signals through the multiway switch and uses the preposed sampling chip in a time-sharing way, realizes the effect of inputting the multipath temperature signals into the singlechip by using one chip, and achieves the aim of reducing the cost.)

1. A time-sharing processing method of temperature input signals of a plurality of thermocouples is characterized by comprising the following steps:

step S1: starting the discharge temperature testing equipment at fixed time, and receiving and recording data of the current channel by the singlechip;

step S2: the single chip microcomputer outputs signals to the multi-path change-over switch through the GPIO, changes a channel of the thermocouple temperature measuring point, conducts the current channel and closes the channel which is sampled completely;

step S3: looping the above steps S1 to S2 until the temperature recording of all channels is completed;

step S4: since it takes a while from opening the channel until the channel operation is stable, the main program timer will start the next read operation at the next interval, and the interval therebetween is used to stabilize the channel operation.

2. A time-sharing processing system for multi-channel thermocouple temperature input signals is characterized by comprising 4 thermocouple temperature measuring points which are arranged in front of a DOC, in front of a DPF, in front of an SCR and in back of the SCR and switch and transmit the temperature to a front chip through a multi-channel transfer switch, wherein the front chip converts the absorbed temperature into an address line information signal and transmits the address line information signal to a single chip microcomputer, and the single chip microcomputer adjusts a conduction object through switch adjustment.

Technical Field

The invention mainly relates to the field of signal processing, in particular to a time-sharing processing method for temperature input signals of multiple thermocouples.

Background

The latest standards for diesel emission technology have reached the sixth national stage. In the technical scheme of the emission post-treatment at this stage, the series operation is realized through a plurality of post-processors such as DOC, DPF, SCR and the like, the exhaust gas discharged by the diesel engine is treated, and catalytic oxidation of HC and CO, filtration of particle components and catalytic reduction treatment of NOx components are respectively realized. This requires real-time knowledge of the temperature status of each node, i.e., each device inlet and outlet, to achieve control over the operation of the post-processor.

The existing technology for measuring the exhaust temperature mainly adopts a multi-channel thermocouple branch circuit to output to a front-end chip, the front-end chip carries out enhancement amplification, AD conversion, temperature calculation, data arrangement and SPI transmission aiming at a thermocouple signal, and the obtained temperature data is transmitted to a single chip microcomputer to be summarized.

With the actual falling of the national six-stage technology in the domestic automobile industry, the demand for emission temperature testing equipment is expanding. In recent years, the technology for temperature thermocouple measurement has been highly integrated in a front chip of thermocouple temperature signal processing. Whereas the front chip constitutes a large proportion of the cost of the product. The pressure of the same kind of products in competition causes the gradual enhancement of the control requirement on the cost of the same kind of products, so that the need to consider how to reduce the cost of the products by reducing the use of the front-end chip is needed.

The published Chinese invention patent, application number CN201410098835.5, patent name: a multi-path K-type thermocouple signal acquisition method is disclosed on the application date: 2014-03-14, the invention relates to a multi-path K-type thermocouple signal acquisition method, which comprises eight parts: the device comprises a thermocouple signal conversion circuit, a voltage reference circuit, a 32-path analog multiplexing circuit, a low-pass differential signal conversion circuit, an ADC (analog-to-digital converter) conversion circuit, a microprocessor circuit, a power supply circuit and an RS485 circuit; the STM32F407 series ARM microprocessor is used as a main part to complete the functions of 32-path analog data gating multiplexing, AD analog signal acquisition, software filtering algorithm processing, AD data framing, RS485 bus communication and the like. The thermocouple signal conversion circuit converts the thermocouple output voltage signal into a form of 5 mV/DEG C for output. The method adopts a 32-path analog gating multiplexer to gate the thermocouples in sequence and then performs temperature data acquisition. The RS485 bus mode is adopted for data transmission, so that the requirement of long-distance transmission can be met, and the requirement that a plurality of acquisition nodes operate in the same system can be met. The acquisition mode of the 16-bit differential ADC is adopted, so that the precision requirement can be met, the noise interference is reduced, and the method has good environmental adaptability.

Disclosure of Invention

The invention provides a method for time-sharing processing of a plurality of paths of thermocouple temperature input signals, aiming at the defects in the prior art, and the method for time-sharing processing of the plurality of paths of thermocouple temperature input signals comprises the following steps:

step S1: starting the discharge temperature testing equipment at fixed time, and receiving and recording data of the current channel by the singlechip;

step S2: the single chip microcomputer outputs signals to the multi-path change-over switch through the GPIO, changes a channel of the thermocouple temperature measuring point, conducts the current channel and closes the channel which is sampled completely;

step S3: looping the above steps S1 to S2 until the temperature recording of all channels is completed;

step S4: since it takes a while from opening the channel until the channel operation is stable, the main program timer will start the next read operation at the next interval, and the interval therebetween is used to stabilize the channel operation.

A time-sharing processing system for multi-channel thermocouple temperature input signals is characterized by comprising 4 thermocouple temperature measuring points which are arranged in front of a DOC, in front of a DPF, in front of an SCR and in back of the SCR and switch and transmit the temperature to a front chip through a multi-channel transfer switch, wherein the front chip converts the absorbed temperature into an address line information signal and transmits the address line information signal to a single chip microcomputer, and the single chip microcomputer adjusts a conduction object through switch adjustment.

The invention has the beneficial effects that: the working capacity of the preposed chip is utilized in a time-sharing manner, the preposed sampling chip is used for converting the multi-path temperature signals in a time-sharing manner through the multi-way switch, the effect that the multi-path temperature signals are input into the single chip microcomputer through one chip is achieved, and the aim of reducing the cost is achieved.

Drawings

FIG. 1 is a flow chart of the present invention;

fig. 2 is a structural view of the present invention.

Detailed Description

As shown in fig. 1-2, the present invention comprises the following steps:

step S1: starting the discharge temperature testing equipment at fixed time, and receiving and recording data of the current channel by the singlechip;

step S2: the single chip microcomputer outputs signals to the multi-path change-over switch through the GPIO, changes a channel of the thermocouple temperature measuring point, conducts the current channel and closes the channel which is sampled completely;

step S3: looping the above steps S1 to S2 until the temperature recording of all channels is completed;

step S4: since it takes a while from opening the channel until the channel operation is stable, the main program timer will start the next read operation at the next interval, and the interval therebetween is used to stabilize the channel operation.

When the device is used, the temperature sampling of the multi-channel thermocouple sensor can be completed by using a front chip in combination with the hardware configuration and the control software of the multi-channel change-over switch, so that the hardware cost of exhaust temperature measurement is effectively reduced.

In addition, the key to realize time-sharing control is that at the same time, the output direction of the address line determines the specific attribution of the conducted input signal. At this moment (after the address is changed, a delay is experienced), the data obtained by the singlechip from the front chip is the temperature signal obtained by pointing to the channel with the address line.

A time-sharing processing system for multi-channel thermocouple temperature input signals is characterized by comprising 4 thermocouple temperature measuring points which are arranged in front of a DOC, in front of a DPF, in front of an SCR and in back of the SCR and switch and transmit the temperature to a front chip through a multi-channel transfer switch, wherein the front chip converts the absorbed temperature into an address line information signal and transmits the address line information signal to a single chip microcomputer, and the single chip microcomputer adjusts a conduction object through switch adjustment.

In use, T1, T2, T3 and T4 are set to respectively represent 4 thermocouple temperature measuring points before DOC, DPF, SCR and SCR, and the technical scheme shares a preposed processing chip through a multi-channel conversion mode so as to reduce the number requirement of the preposed chips to the minimum.

As shown in fig. 2, the multiplexer switch used is a dedicated integrated circuit chip dedicated to multiplexing of thermocouple circuits.

The two-way wiring of the thermocouple can be switched and transferred simultaneously. The single chip microcomputer controls the potential of the address line through the output of the GPIO to realize the adjustment of the conducting object.

The above-described embodiments are merely illustrative of the principles and utilities of the present patent application and are not intended to limit the present patent application. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of this patent application. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical concepts disclosed in the present application shall be covered by the claims of this patent application.