Special vehicle brake temperature warning system and method based on thermocouple

Abstract

The application provides a special vehicle brake temperature early warning system and method based on thermocouple, which comprises a signal sampling module, a control module and an early warning module; the signal sampling module comprises thermocouple temperature sensors, thermal resistance temperature sensors, conditioning circuits and sampling circuits; the thermocouple temperature sensors are multiple and are used for measuring the temperatures at different positions of the special vehicle brake, so that the obtained result is more accurate; the thermal resistance temperature sensors are used for measuring the cold end temperature of the thermocouple temperature sensors and compensating the cold end temperature of the thermocouple; the control unit calculates and processes the temperature signals sampled by the thermocouple and the thermal resistance temperature sensors, issues instructions to the early warning module according to the calculation result and controls the working of the early warning module; when the temperature is too high, timely early warning is performed, brake failure and vehicle driving failure are avoided, and driving safety can be ensured.

Description

Technical Field

[0001] This invention relates to the field of automotive safety testing technology, and in particular to a characteristic vehicle brake temperature early warning system and method based on thermocouples. Background Technology

[0002] Brakes on special vehicles operate in harsh environments with high temperatures and abundant dust and sand. Especially during rapid braking, the brake temperature rises rapidly, causing metal-to-metal adhesion, which can lead to brake failure and render the vehicle immobile. Therefore, it is necessary to accurately measure the vehicle's brake temperature in real time to provide early warning of situations where the brake temperature is too high and the brakes may seize up.

[0003] Thermocouple temperature sensors have advantages such as simple structure, easy manufacturing, wide temperature range, low thermal inertia, and high accuracy, and can be used as temperature measurement sensors for special vehicle brakes.

[0004] A thermocouple consists of two conductors with different properties. The temperature difference between the hot and cold junctions generates a thermoelectric potential within the thermocouple, and the temperature difference between the two junctions can be calculated by measuring the magnitude of the thermoelectric potential. However, since the cold junction of a thermocouple temperature sensor is not at 0°C, the measured temperature will introduce errors. And in existing technologies, cold junction temperature compensation for thermocouple temperature sensors is rarely considered.

[0005] Furthermore, the ambient temperature of the brakes in special vehicles is high, and the components of the hardware circuit cannot function properly at this temperature.

[0006] Therefore, a new technological approach is urgently needed to solve the above problems. Summary of the Invention

[0007] In view of this, the present invention provides a special vehicle brake temperature warning system and method based on thermocouples, which can accurately measure the temperature of the brake and provide timely warning when the temperature is too high, so as to avoid brake failure and vehicle inability to drive, and ensure driving safety. In addition, the present invention takes into account the cold junction temperature compensation of the thermocouple temperature sensor, so that the temperature obtained is more accurate. Furthermore, the present invention places the hardware circuit of the warning system in a unit box made of heat-insulating material, which can prevent the hardware circuit from failing to work properly due to high temperature environment.

[0008] The present invention provides a special vehicle brake temperature warning system based on thermocouples, including a signal sampling module, a control module and a warning module;

[0009] The signal sampling module is used to collect the temperature signal of the special vehicle brake and transmit it to the control module. The control module calculates and processes the signal and controls the early warning module to work based on the processed signal.

[0010] The signal sampling module includes a thermocouple temperature sensor, a resistance temperature sensor, a conditioning circuit, and a sampling circuit.

[0011] The thermocouple temperature sensor is used to detect the temperature of the vehicle brake; the output terminal of the thermocouple temperature sensor is connected to the input terminal of the conditioning circuit.

[0012] The output of the conditioning circuit is connected to the input of the sampling circuit;

[0013] The resistance temperature sensor is used to detect the cold junction temperature of the thermocouple temperature sensor; the output terminal of the resistance temperature sensor is connected to the input terminal of the sampling circuit.

[0014] The output of the sampling circuit is connected to the control input of the control module.

[0015] The control output terminal of the control module is connected to the control input terminal of the early warning module.

[0016] Furthermore, it also includes a unit box; the unit box is a sealed box made of heat-insulating material to isolate the high temperature of the environment where the brake is located; the conditioning circuit and the sampling circuit are both located inside the unit box.

[0017] Furthermore, there are multiple thermocouple temperature sensors;

[0018] The hot junction of the thermocouple temperature sensor is evenly distributed in the brake to detect the temperature at different locations in the brake; the cold junction of the thermocouple temperature sensor is mounted on the unit box.

[0019] The detection end of the resistance temperature sensor is mounted on the unit box.

[0020] Another aspect of the present invention provides a method for temperature warning of special vehicle brakes based on thermocouples, comprising the following steps:

[0021] S1. After the special vehicle is started, obtain the average temperature T detected by the thermocouple temperature sensors on the left and right brakes of the vehicle at time t. Cl T Cr The temperature T detected by the resistance temperature sensor Rl T Rr ;

[0022] S2. After receiving the temperature signal, the control module performs thermocouple cold junction temperature compensation and calculates the actual temperature T of the left and right brakes of the vehicle. tl T tr The specific steps include:

[0023] S21. Based on the temperature T sampled by the thermocouple temperature sensor Cl T CrConsult the thermocouple temperature sensor calibration table to obtain the temperature T. Cl T Cr Corresponding thermoelectric potential

[0024] S22. Based on the temperature T sampled by the resistance temperature sensor. Rl T Rr Consult the thermocouple temperature sensor calibration table to obtain the temperature T. Rl T Rr Corresponding thermoelectric potential

[0025] S23. Add the thermoelectric potential corresponding to the temperature sampled by the thermocouple temperature sensor at time t to the thermoelectric potential corresponding to the temperature sampled by the resistance temperature sensor, specifically:

[0026]

[0027]

[0028] in, These are the thermoelectric potentials corresponding to the actual temperatures of the left and right brakes of the vehicle in the thermocouple temperature sensor calibration table, respectively.

[0029] S24. Consult the thermocouple temperature sensor calibration table to obtain the thermoelectric potential. The corresponding temperatures T tl T tr ;

[0030] S3. Calculate the temperature difference T between the two brakes. w and the respective temperature rise rate T of the two brakes v and obtain T v The maximum value is as follows:

[0031] T w =|T tl -T tr |

[0032] T vl =|T tl -T (t-1)l |·f

[0033] T vr =|T tr -T (t-1)r |·f

[0034] Where f is the sampling frequency, T vl T vr These represent the temperature rise rates of the left and right brakes of the vehicle, respectively, T. (t-1)l T (t-1)rThese are the temperatures of the left and right brakes of the vehicle at time (t-1);

[0035] S4. Calculate the temperature warning index T. θ The calculation method is as follows:

[0036] T θ =α1T p +α2T w +α3T vmax

[0037] Among them, T p The result of the brake temperature determination, T w T represents the temperature difference between the two brakes at that moment. vmax =max{T vl T vr}, α1, α2, α3 are T p T w T vmax The weighting coefficients are α1+α2+α3=1.

[0038] S5. Determine the temperature warning indicator T θ If the value is greater than the first threshold T1, proceed to S6; otherwise, do not issue a warning.

[0039] S6. Determine the temperature warning indicator T θ If the value is greater than the second threshold T2, upload the first-level alarm information; otherwise, upload the second-level alarm information.

[0040] S7. Store the calculated brake temperature information and warning information for later retrieval.

[0041] Furthermore, in step S4, the result T of the brake temperature determination... p The judgment method is as follows:

[0042] Set a temperature threshold T;

[0043]

[0044] Where M1, M2, and M3 are the judgment results T under different conditions. p The value of .

[0045] The present invention has the following beneficial effects:

[0046] 1. The thermocouple-based special vehicle brake temperature early warning system and method provided by the present invention can provide timely warning when the vehicle brake temperature is too high, so as to avoid brake failure and prevent the vehicle from being unable to drive, thus ensuring driving safety.

[0047] 2. This invention takes into account the cold junction temperature compensation of the thermocouple temperature sensor, resulting in a more accurate temperature; furthermore, this invention considers the temperature difference between the two brakes and the rate of temperature rise when calculating the temperature warning index, making the consideration more comprehensive and the result more accurate.

[0048] 3. The early warning system provided by the present invention has a simple structure and a wide temperature measurement range. Furthermore, the present invention places the hardware circuit part of the early warning system in a unit box made of heat-insulating material, which can prevent the hardware circuit from failing to work properly due to high temperature environment. Attached Figure Description

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0050] Figure 1 This is a structural diagram of a thermocouple-based temperature warning system for special vehicle brakes.

[0051] Figure 2 This is a flowchart of a special vehicle brake temperature early warning method based on thermocouples. Detailed Implementation

[0052] The present invention will now be clearly and completely described in conjunction with the accompanying drawings and embodiments.

[0053] The present invention provides a special vehicle brake temperature warning system based on thermocouples, including a signal sampling module, a control module and a warning module;

[0054] The signal sampling module is used to collect the temperature signal of the special vehicle brake and transmit it to the control module. The control module calculates and processes the signal and controls the early warning module to work based on the processed signal.

[0055] The signal sampling module includes a thermocouple temperature sensor, a resistance temperature sensor, a conditioning circuit, and a sampling circuit.

[0056] The thermocouple temperature sensor is used to detect the temperature of the vehicle brake; the output terminal of the thermocouple temperature sensor is connected to the input terminal of the conditioning circuit.

[0057] The output of the conditioning circuit is connected to the input of the sampling circuit; the conditioning circuit filters and amplifies the temperature signal sampled by the thermocouple temperature sensor, and transmits the filtered and amplified signal to the sampling circuit.

[0058] The resistance temperature sensor is used to detect the cold junction temperature of the thermocouple and is used for thermocouple cold junction temperature compensation; the output terminal of the resistance temperature sensor is connected to the input terminal of the sampling circuit.

[0059] The output of the sampling circuit is connected to the control input of the control module; the sampling circuit converts the analog signal filtered and amplified by the conditioning circuit and the analog signal obtained by the resistance temperature sensor into a digital signal, and transmits the digital signal to the control module; the existing technical means used in the conditioning circuit and sampling circuit will not be described in detail here.

[0060] The control output terminal of the control module is connected to the control input terminal of the early warning module; the control module is the on-board controller of the special vehicle itself.

[0061] In this embodiment, the early warning system further includes a unit box; the unit box is a sealed box made of heat-insulating material, used to isolate the high temperature of the environment where the brake is located;

[0062] The conditioning circuit and the sampling circuit are both located inside the unit box;

[0063] The unit box is equipped with a plug, and the output terminal of the thermocouple temperature sensor is connected to the conditioning circuit through the plug.

[0064] The unit box is installed on the stationary part of the brake.

[0065] In this embodiment, there are multiple thermocouple temperature sensors;

[0066] The hot junction of the thermocouple temperature sensor is evenly distributed in the brake to detect the temperature at different locations in the brake; the cold junction of the thermocouple temperature sensor is mounted on the unit box.

[0067] The detection end of the resistance temperature sensor is mounted on the unit box.

[0068] In another aspect, the present invention provides an early warning method based on the temperature early warning system described above, comprising the following steps:

[0069] S1. After the special vehicle is started, obtain the average temperature T detected by the thermocouple temperature sensors on the left and right brakes of the vehicle at time t. Cl T Cr The temperature T detected by the resistance temperature sensor Rl T Rr ;

[0070] S2. After receiving the temperature signal, the control module performs thermocouple cold junction temperature compensation and calculates the actual temperature T of the left and right brakes of the vehicle. tl T tr The specific steps include:

[0071] S21. Based on the temperature T sampled by the thermocouple temperature sensor Cl T CrConsult the thermocouple temperature sensor calibration table to obtain the temperature T. Cl T Cr Corresponding thermoelectric potential

[0072] S22. Based on the temperature T sampled by the resistance temperature sensor. Rl T Rr Consult the thermocouple temperature sensor calibration table to obtain the temperature T. Rl T Rr Corresponding thermoelectric potential

[0073] S23. Add the thermoelectric potential corresponding to the temperature sampled by the thermocouple temperature sensor at time t to the thermoelectric potential corresponding to the temperature sampled by the resistance temperature sensor, specifically:

[0074]

[0075]

[0076] in, These are the thermoelectric potentials corresponding to the actual temperatures of the left and right brakes of the vehicle in the thermocouple temperature sensor calibration table, respectively.

[0077] S24. Consult the thermocouple temperature sensor calibration table to obtain the thermoelectric potential. The corresponding temperatures T tl T tr ;

[0078] S3. Calculate the temperature difference T between the two brakes. w and the respective temperature rise rate T of the two brakes v and obtain T v The maximum value is as follows:

[0079] T w =|T tl -T tr |

[0080] T vl =|T tl -T (t-1)l |·f

[0081] T vr =|T tr -T (t-1)r |·f

[0082] Where f is the sampling frequency, T vl T vr These represent the temperature rise rates of the left and right brakes of the vehicle, respectively, T. (t-1)l T (t-1)rThese are the temperatures of the left and right brakes of the vehicle at time (t-1);

[0083] S4. Calculate the temperature warning index T. θ The calculation method is as follows:

[0084] T θ =α1T p +α2T w +α3T vmax

[0085] Among them, T p The result of the brake temperature determination, T w T represents the temperature difference between the two brakes at that moment. vmax =max{T vl T vr}, α1, α2, α3 are T p T w T vmax The weighting coefficients are α1+α2+α3=1.

[0086] S5. Determine the temperature warning indicator T θ If the value is greater than the first threshold T1, proceed to S6; otherwise, do not issue a warning.

[0087] S6. Determine the temperature warning indicator T θ If the value is greater than the second threshold T2, upload the first-level alarm information; otherwise, upload the second-level alarm information.

[0088] S7. Store the calculated brake temperature information and warning information for later retrieval.

[0089] In this embodiment, in step S4, the determination result T of the brake temperature p The judgment method is as follows:

[0090] Set a temperature threshold T;

[0091]

[0092] Where M1, M2, and M3 are the judgment results T under different conditions. p The values ​​of M1, M2, and M3 are derived from actual working experience of special vehicle brakes.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for early warning of brake temperature in special vehicles based on thermocouples, characterized in that: Including the following steps: S1. After the special vehicle is started, obtain the average temperature T detected by the thermocouple temperature sensors on the left and right brakes of the vehicle at time t. Cl T Cr The temperature T detected by the resistance temperature sensor Rl T Rr ; S2. After receiving the temperature signal, the control module performs thermocouple cold junction temperature compensation and calculates the actual temperature T of the left and right brakes of the vehicle. tl T tr The specific steps include: S21. Based on the temperature T sampled by the thermocouple temperature sensor Cl T Cr Consult the thermocouple temperature sensor calibration table to obtain the temperature T. Cl T Cr Corresponding thermoelectric potential , ; S22. Based on the temperature T sampled by the resistance temperature sensor. Rl T Rr Consult the thermocouple temperature sensor calibration table to obtain the temperature T. Rl T Rr Corresponding thermoelectric potential ; S23. Add the thermoelectric potential corresponding to the temperature sampled by the thermocouple temperature sensor at time t to the thermoelectric potential corresponding to the temperature sampled by the resistance temperature sensor, specifically: in, , These are the thermoelectric potentials corresponding to the actual temperatures of the left and right brakes of the vehicle in the thermocouple temperature sensor calibration table, respectively. S24. Consult the thermocouple temperature sensor calibration table to obtain the thermoelectric potential. , The corresponding temperatures T tl T tr ; S3. Calculate the temperature difference T between the two brakes. w and the temperature rise rate of each of the two brakes and obtain The maximum value is as follows: Where f is the sampling frequency, , These represent the temperature rise rates of the left and right brakes of the vehicle, respectively. , These are the temperatures of the left and right brakes of the vehicle at time (t-1); S4. Calculate the temperature warning index The calculation method is as follows: Among them, T p The result of the brake temperature determination, T w The temperature difference between the two brakes at that moment. α1, α2, and α3 are T p T w T vmax The weighting coefficients, and ; Brake temperature determination result T p The judgment method is as follows: Set a temperature threshold T; Where M1, M2, and M3 are the judgment results T under different conditions. p The value; S5. Determine temperature warning indicators If the value is greater than the first threshold T1, proceed to S6; otherwise, do not issue a warning. S6. Determine temperature warning indicators If the value is greater than the second threshold T2, upload the first-level alarm information; otherwise, upload the second-level alarm information. S7. Store the calculated brake temperature information and warning information for later retrieval.

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