KR20020061089A - Engine Torque Measurement System on Car and the Operating Method - Google Patents

Abstract

PURPOSE: A system for measuring engine torque of vehicle and operating method of the same are provided to detect RPM of the engine, acceleration of the vehicle and so on by opening degrees of a throttle valve while driving the vehicle on an actual road and to calculate the engine torque of the vehicle using the detected value. CONSTITUTION: A system includes a sensor part(10) including an RPM detective sensor(16), an acceleration sensor(14) and a throttle position sensor(12); a database part(40) storing specification and characteristic performance of a vehicle; a control part receiving signal from the sensor part and calculating torque of the vehicle using the signal, data stored in the database part and the following formula: T=(gamma/(isxifxetaxt)) x (alpha(W + Delta W) + F_0 + F_2x ((0.06x2xphixrxexn)/(i_sxi_f))¬2)x(kgfxm), where W is gross weight of the vehicle(kgf), Delta W is equivalent inertia weight(kgf) generated during acting on rotating parts such as an engine, T is torque(kgfxm) of the engine, i_s is speed gear ratio of a transmission, i_f is final reduction gear ratio of the transmission, eta is efficiency of the transmission, gamma is dynamic load radius of a tire, meaning radius of the tire pressed during driving of the vehicle, F_0 is coefficient of rolling resistance, F_2 is wind resistance coefficient, n is RPM of the engine, t is mechanical advantage for an automatic transmission(1.0 for manual transmission) and e is speed ratio for the automatic transmission(1.0 for manual transmission); and a monitor, connected with the control part to display signal input by the sensor part to the control part.

Description

Engine Torque Measurement System on Car and the Operating Method

The present invention relates to a system for measuring engine torque of a vehicle and a method of operating the vehicle, and more particularly, to detect an engine speed and acceleration for each throttle valve opening amount while driving a vehicle directly on a road, and to use the detected values. By constructing the engine torque value objectively, the engine torque can be accurately measured even without expensive equipment including chassis dynamo, and even small companies such as used car dealers can give objectivity to the valuation of the vehicle. The present invention relates to an engine torque measurement system for a vehicle and a method of operating the same, which enable a low cost and easy measurement.

In a vehicle, an engine is one of the most important requirements for driving a vehicle, and the torque of the engine is a factor that indicates the actual performance of the engine. Therefore, in order to accurately evaluate the performance of the vehicle, it is important to measure the engine torque of the vehicle accurately.

In general, the engine torque measurement system includes a chassis dynamo and a plurality of sensors and computer equipment in a predetermined laboratory. It is composed.

However, in order to construct a conventional engine torque measurement system, expensive equipment such as chassis dynamo must be purchased and installed inevitably. Therefore, a problem of not only having a separate test room but also a large cost is required. there was.

In particular, in the case of used car sales, in order to accurately evaluate the vehicle performance, although it is most important to accurately measure the engine performance by measuring the engine torque value, small used car dealers use a conventional engine torque measurement system that is expensive. It was almost impossible to equip, and accordingly, there was an unreasonable point that most of the used car sales were only able to roughly evaluate the value of the vehicle considering only the total mileage of the vehicle and the presence of a traffic accident.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, while driving the vehicle directly on the road, by detecting the engine speed (rpm) and the acceleration of the vehicle for each throttle valve opening amount, the detected value It is possible to calculate the engine torque value of the vehicle using the engine, so that the engine torque can be accurately measured without expensive equipment including chassis dynamo, and used car dealers can also have the engine torque measurement system at low cost. The purpose is to provide a vehicle engine torque measurement system that can accurately evaluate the value of used cars sold.

1 is a block diagram showing an embodiment of a system for measuring engine torque of a vehicle according to the present invention;

2 is a flowchart showing an embodiment of a method for operating an engine torque measurement system for a vehicle according to the present invention;

<Description of Symbols for Major Parts of Drawings>

10: sensor unit, 12: throttle position sensor, 14: acceleration sensor, 16: RPM detection sensor, 18: vehicle speed sensor, 20: control unit, 22: data acquisition unit, 24: memory card, 26: computer, 30: Monitor, 40: database portion, 50: air condition detection means.

In order to achieve the above object, the present invention, an RPM sensor for detecting the engine RPM of the vehicle, an acceleration sensor for detecting the acceleration of the vehicle, a sensor unit including a throttle position sensor for detecting the opening amount of the throttle valve; A database unit for storing data about the specification and the unique performance of the vehicle; Receives the signal values detected by the sensor unit, using the signal values input from the sensor unit and the data values stored in the database unit and the following equation (1)

A control unit for calculating a torque value of the vehicle; And a monitor connected to the control unit for displaying each signal value input from the sensor unit to the control unit.

In addition, the present invention, a system installation step of installing a data acquisition unit, a monitor connected to the throttle position sensor, the acceleration sensor, the RPM sensor, the vehicle speed sensor, the memory card in the appropriate portion of the vehicle to measure the engine torque; A driving start step of driving the vehicle on a road after the system installation step; After the driving start step, a measurement storage step of receiving the values detected from the RPM sensor, the acceleration sensor, and the vehicle speed sensor while increasing the opening amount of the throttle valve by a predetermined value and displaying them on the monitor and storing them in the memory card at the same time ; Through the measurement storage step, the RPM value acceleration value vehicle speed value for each opening amount of the throttle valve stored in the memory card, the specification and the unique performance of the vehicle stored in the database, and the equation (1)

And a torque value calculating step of calculating torque values according to changes in RPM value for each opening amount of the throttle valve.

Hereinafter, a preferred embodiment of an engine torque measurement system and a method of operating the vehicle according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a system for measuring engine torque of a vehicle according to the present invention. As shown in the drawing, the present invention includes a sensor unit 10, a control unit 20, a monitor 30, and a database unit 40. It is composed.

The sensor unit 10 includes a throttle position sensor 12, an acceleration sensor 14, and an RPM sensor 16. The throttle position sensor 12 is installed in the throttle valve of the throttle body to detect the opening amount of the throttle valve according to the operation of the accelerator pedal, and is configured to output the detected opening degree of the throttle valve as a voltage value. The acceleration sensor 14 is installed on the vehicle body between the shift lever and the parking brake of the vehicle, and is configured to detect the acceleration generated in the front and rear directions when the vehicle is driven and output the voltage value corresponding thereto.

In addition, the RPM sensor 12 is a sensor for detecting the engine speed (rpm), the spark signal detector 12a and the spark signal installed to detect the spark signal of the engine periodically generated from the ignition coil, and the spark signal The tachometer 12b is connected to the detector 12a and receives the spark signal sensed by the spark signal detector 12a and converts the spark signal into a voltage value indicating the engine speed rpm.

The database unit 40 stores data about the specifications and the unique performance of the vehicle to be tested. Such specifications and specific performance may include the total weight of the vehicle, the equivalent inertia weight, the speed gear ratio of the transmission, the gear ratio of the gearbox of the transmission, the transmission efficiency, the dynamic load radius of the tire, the rolling resistance coefficient, the air resistance value, and the like.

The control unit 20 is connected to an output terminal of the sensor unit 10 to receive signal values such as an opening amount, an engine speed (rpm), an acceleration of the throttle valve sensed by the sensor unit 10. Reference numeral 10a illustrates a junction box for extending the input channel of the controller 20. In addition, the control unit 20 outputs the opening amount, engine speed (rpm), and acceleration values of the throttle valve input from the sensor unit 10 to the monitor 30 to be displayed in a graph or / and a number. At the same time, the signal values input from the sensor unit 10, the data values stored in the database unit 40, and the torque value of the vehicle are calculated using the following equation (1).

In the above, a is the acceleration generated in the vehicle (m / sec ² ),

W is the total weight of the vehicle (kgf),

ΔW is the equivalent inertia weight (kgf)

T is the torque of the engine (kgf × m),

is the speed gear ratio of the transmission,

if is the derailleur gear ratio of the transmission,

η is the transmission efficiency,

γ (gamma) is the dynamic load radius of the tire, which means the radius of the tire pressed when the vehicle is running,

F ₀ is rolling resistance coefficient (kgf),

F ₂ is the air resistance value (kgf × sec ² / m ² ),

n is the engine speed (rpm),

t is the power ratio in the automatic transmission (1.0 in manual transmission),

e means the speed ratio in the automatic transmission (1.0 in manual transmission).

The rolling resistance coefficient (F ₀ ) and the air resistance value (F ₂ ) may be measured as a fixed constant value through the driving performance test running on the road to measure the vehicle under test. Therefore, in the above formula (1), all items except the torque T, the acceleration a, and the engine speed n of the engine are treated as constants, thereby measuring the acceleration a and the engine speed n. The torque T of the engine between the lower surfaces can be calculated.

The derivation process of Equation (1) is described as follows. Hereinafter, the same symbol as the above formula (1) means the same item.

The driving force (F) of the vehicle is the torque generated from the engine is a force coming from the wheel through the power train, It is expressed as

The driving resistance R of the vehicle means all resistance values received while the vehicle is driving, and therefore R = F _O + Ra + Ri + Rg (kgf).

Here, F _O is the rolling resistance which is the resistance between the road surface and the tire when the vehicle is running

Ra is the air resistance generated by the air when the vehicle is running.

Ri is an acceleration resistance generated when the vehicle accelerates while driving. Represented by

Rg is the gradient resistance received by the slope of the road when the vehicle is running.

And, the free driving force (P) at the time of acceleration of the vehicle

P = F-R = F-(F _O + Ra + Ri + Rg).

Here, Rg becomes '0' when the vehicle is driven in a place where there is no inclination of the road, and the driving force P is also used to accelerate, so it becomes '0'.

Therefore, Ri = F-(F ₀ + Ra).

And, Because of,

Is,

If you put this expression in terms of acceleration (a),

Becomes

If this is summed up again into the torque T item of the engine, Equation (1) is derived.

By adding the vehicle speed sensor 18 for detecting the speed of the vehicle to the sensor unit 10, the equation (1) may be simplified by directly using the vehicle speed value.

The control unit 20 may include a data accumulation unit 22, a memory card 24, and a computer 26.

In this case, the data acquisition unit 22 is configured to collect signal values input from the sensor unit 10 and display the graphs and / or numerical values on the monitor 30. 24 is configured to receive and store the opening amount, engine speed (rpm), and acceleration values of the throttle valve collected by the database unit 40. The computer 26 is connected to the database unit 40 and substitutes the data values stored in the database unit 40 and the data values stored in the memory card 24 into the equation (1). It is programmed to calculate the torque value of the engine.

When the control unit 20 is composed of a plurality of components separated in this way, the data acquisition unit 22 in which the sensor unit 10 and the memory card 24 are coupled when driving and testing a vehicle on a road. ) And the monitor 30 is mounted on the vehicle to measure the acceleration values according to the change of the engine speed for each opening amount of the throttle valve and to store the measured data in the memory card 24, after the measurement is completed. And a memory card 24 having stored therein measurement data coupled to the computer 26 to calculate an engine torque value. In this case, the configuration of the equipment mounted on the vehicle is simplified, so that the measurement can be quickly proceeded.

In addition, the control unit 20 is further coupled to the outside air condition detecting means 50 for detecting the outside air state of the road on which the vehicle is driven, and receives the values detected by the outside air condition detecting means 50 to receive a standard After converting into a correction factor for converting into values in the case of an external air condition (20 ° C, 736.6 mmHg, zero wind), programming to correct the torque value of the engine calculated by Equation (1) with the correction factor. As a result, a reliable engine torque value can be calculated. The outside air condition detecting means 50 may include a wind speed sensor 51, a wind direction sensor 52, a temperature sensor 53, an atmospheric pressure sensor 54, and a humidity sensor 55. 50 may be installed on a road on which the test vehicle runs, collect and store the measured values in a predetermined memory device, and then transmit the measured values to the control unit 20. Reference numeral 60 denotes a printer.

As shown in FIG. 2, a method of operating an engine torque measurement system for a vehicle having the above configuration includes a system installation step S10, a driving start step S20, a measurement storage step S30, and a torque value calculation step. It comprises a (S40).

In the system installation step (S10), by opening the throttle position sensor 12, the acceleration sensor 14, the RPM sensor 16 and the vehicle speed sensor 18 in the appropriate portion of the vehicle, the opening amount, acceleration of the throttle valve And detecting the engine speed and the vehicle speed, and installing and connecting the data acquisition unit 22 to receive the detected signal values from each of the sensors 12 to 18, and the data acquisition unit. By connecting the monitor 30 and the memory card 24 to 22, the signal values input to the data acquisition unit 22 are displayed on the monitor 30 and stored in the memory card 24 at the same time. Install. After the system installation step S10 is completed, a driving start step S20 for driving the vehicle along a horizontal road is executed.

Then, in the measurement storage step (S30) performed after the driving start step (S20), while increasing the opening amount of the throttle valve by a predetermined value, the engine speed, acceleration and vehicle speed detected by the sensor unit 10 Is inputted to the data acquisition unit 22 to be displayed on the monitor 30 and stored in the memory card 24.

That is, in the measurement storage step (S30), the vehicle speed value and the engine speed value increase while the vehicle continues to run while the operator keeps the opening amount of the throttle valve displayed on the monitor 30 constant. The acceleration value is shown to be decreased, and these values are displayed on the monitor 30 and stored on the memory card 24.

When the acceleration value becomes '0' or when the engine speed increases to the highest threshold value (6000 to 6500 rpm), it is difficult to expect any further change, so that the operator cannot change the throttle valve displayed on the monitor 30. If the vehicle continues to run while the opening amount is increased by a certain amount, the acceleration value, the engine speed (rpm) and the vehicle speed indicate another change while the values are displayed on the monitor 30 and the memory card at the same time. Will be stored at (24).

As described above, when the operator repeats the operation of continuously driving the vehicle while increasing the opening amount of the throttle valve by a predetermined amount, the memory card 24 changes the engine speed rpm for each opening amount of the throttle valve. Acceleration values are stored. As a method for driving the vehicle while the operator keeps the opening amount of the throttle valve constant, the operator adjusts the response force applied to the accelerator pedal while viewing the opening amount value of the throttle valve displayed on the monitor 30, A separate clamp may be used such that the accelerator pedal is pressed by a predetermined amount.

This measurement storage step (S30) may be composed of an initial state setting step (S32), a storage step (S34), a throttle valve check step (S36) and a return step (S38).

In the initial state setting step S32, the operator adjusts so that the vehicle continues to run while the opening amount of the throttle valve is maintained at 5% while watching the monitor 30. Then, after the change of the vehicle speed value and the acceleration value according to the change of the engine speed (rpm) when the throttle valve is opened at 5% is detected and input by the sensor unit 10, the monitor 30 Is stored in the memory card 24 and displayed at the same time.

In addition, while the storage step S34 is performed, it is repeatedly checked whether the acceleration value is lowered to '0' or the engine speed is increased to the highest threshold value (6000 to 6500 rpm), and the acceleration value is lowered to '0'. If the engine speed has been increased to the highest threshold, then the throttle valve check step S36 is executed to check whether the throttle valve is 100% open.

If the throttle valve is not 100% open in the throttle valve check step S36, by increasing the opening amount of the throttle valve by 5% and executing the return step S38 of returning to the storage step S34. Measure and store the engine speed (rpm), acceleration and vehicle speed with the throttle valve open.

The torque value calculating step (S40), after the end of the measurement storage step (S30), that is, by the computer 26 after confirming that the throttle valve is 100% open in the throttle valve check step (S36) This step is executed. In this torque value calculation step (S40), the engine speed (rpm) acceleration and speed data for each opening amount of the throttle valve stored in the memory card 24 through the measurement storage step (S30), and the database unit ( The engine torque value according to the change of the engine speed (rpm) is calculated for each opening amount of the throttle valve using the specifications and the unique performance data of the vehicle stored in 40) and the above equation (1).

On the other hand, after the torque value calculation step (S40), the outside air condition detection step (S50), correction coefficient derivation step (S60) for correcting the calculated torque value to a standard outside air condition (20 ℃, 736.6mmHg, zero wind) ) And a torque value correction step S70 may be further included.

In the outside air condition detecting step (S50), by the wind speed sensor 51, the wind direction sensor 52, the temperature sensor 53, the atmospheric pressure sensor 54 and the humidity sensor 55 is installed on the road on which the vehicle travels, It is configured to detect the wind direction, wind speed, temperature, atmospheric pressure and humidity of the area. In the derivation of the correction coefficient (S60), after receiving the values detected through the external air state detection step (S50) from the computer 26, a correction coefficient for converting the input values into values of a standard outdoor air state To.

In the torque value correcting step S70, the torque values calculated through the torque value calculating step S40 are corrected by the correction coefficient derived through the correction coefficient deriving step S60, thereby providing an objective standard outdoor state. This is to derive the engine torque value at.

As can be seen by the above embodiments, according to the engine torque measurement system and operating method of the vehicle according to the present invention, while driving the vehicle directly on the road, the engine speed (rpm) and acceleration for each opening amount of the throttle valve As a result, it is possible to derive an objective engine torque value by using the sensed values, thereby having an economic effect of accurately measuring engine torque without expensive equipment including chassis dynamo. In particular, even small companies such as used car dealerships can be equipped with an engine torque measurement system at a low cost, thereby measuring the engine torque value of the used car and improving reliability in evaluating the value of the vehicle.

Although the engine torque measuring system and the operating method of the vehicle according to the embodiments of the present invention have been described above, the present invention is not limited thereto, and those skilled in the art will be able to variously modify and apply the same.

Claims (3)

A sensor unit including an RPM sensor for detecting engine RPM of the vehicle, an acceleration sensor for detecting acceleration of the vehicle, and a throttle position sensor for detecting an opening amount of the throttle valve; A database unit for storing data about the specification and the unique performance of the vehicle; Receives the signal values detected by the sensor unit, using the signal values input from the sensor unit and the data values stored in the database unit and the following equation (1) A control unit for calculating a torque value of the vehicle; And, And a monitor connected to the control unit to display respective signal values input from the sensor unit to the control unit. The method of claim 1, The control unit is coupled to the outside air condition detection means including at least one sensor of the wind speed sensor, wind direction sensor, temperature sensor, atmospheric pressure sensor, humidity sensor, Receiving the values detected from the outside air condition detecting means and converting them into a correction coefficient for converting the values into a standard outside air condition and correcting the torque value calculated by Equation (1) with the correction coefficient. Engine torque measurement system for vehicles. A system installation step of installing a throttle position sensor, an acceleration sensor, an RPM sensor, a vehicle speed sensor, a data acquisition unit to which a memory card is connected, and a monitor at an appropriate portion of a vehicle to measure engine torque; A driving start step of driving the vehicle on a road after the system installation step; After the driving start step, a measurement storage step of receiving the values detected from the RPM sensor, the acceleration sensor, and the vehicle speed sensor while increasing the opening amount of the throttle valve by a predetermined value and displaying them on the monitor and storing them in the memory card at the same time ; Through the measurement storage step, the RPM value acceleration value vehicle speed value for each opening amount of the throttle valve stored in the memory card, the specification and the unique performance of the vehicle stored in the database, and the equation (1) And a torque value calculating step of calculating torque values according to a change in RPM value for each opening amount of the throttle valve.