CN112033507A

CN112033507A - Method for detecting vehicle mass of whole vehicle through road test

Info

Publication number: CN112033507A
Application number: CN202010875768.9A
Authority: CN
Inventors: 朱卫萍
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-18
Filing date: 2020-08-18
Publication date: 2020-12-04

Abstract

A method for detecting the quality of the whole vehicle by road test includes such steps as calibrating the maximum torque of engine or the maximum net torque of engine Mb1 by road test or bench test, setting the maximum torque Mb2 to Mb1 of vehicle under test condition, selecting 0.92-1, when the quality G2 of whole vehicle is unknown, and after the speed of vehicle is detected, the speed variator is engaged, the accelerator pedal is stepped to rated power position and stabilized, and when the speed of engine is higher than the maximum speed nm, the vehicle is engaged to slide freely, or the rolling resistance coefficient and air resistance coefficient of wheel in reference temp state or running resistance coefficient are not changed, the vehicle is not required to slide freely, and the engine torque balance equation in standard environment state is detected, and calculating to obtain the finished automobile mass G2.

Description

Method for detecting vehicle mass of whole vehicle through road test

Technical Field

A method for detecting the mass of a whole vehicle in a road test is to install a detector or an OBD of a multidimensional acceleration sensor on the vehicle, and detect the mass of the whole vehicle when the vehicle is loaded with goods and runs on a road surface, and belongs to the technical field of vehicle detection.

Background

In the prior art, the whole vehicle mass of a vehicle for loading cargos is usually measured on a weighbridge, and the weighbridge is usually measured and controlled at an entrance of the highway in order to prevent an overloaded vehicle from damaging the highway. In order to overcome the defects of the prior art, a method for detecting the quality of the whole vehicle by a road test is adopted, the quality of the whole vehicle is detected by the road test, and the detected quality can be transmitted to a management department for effective supervision.

Disclosure of Invention

A method for detecting the mass of a whole vehicle in a road test is characterized in that a detector or an OBD (on-board diagnostics) of a multi-dimensional acceleration sensor is arranged on the vehicle, and the detector can measure the acceleration in the advancing direction of the vehicle and the road surface gradient. After the vehicle is weighed, the maximum engine torque Mb1 and the corresponding vehicle speed V1 are calibrated by adopting a road test or a bench test, or the simplified calibration Mb1 is the maximum output net engine torque without containing the loss torque of the engine accessories. When the road test is used for neutral coasting, the wheel rolling resistance coefficient and the air resistance coefficient of the reference environment temperature state or the running resistance coefficient Fr ═ Fr1/(G1 Xg) can be calibrated, Fr1 is the running resistance of the reference environment temperature state at the vehicle speed point of neutral coasting V1, and G1 is the calibrated known vehicle mass. And in a certain period after calibration, the technical conditions of an engine, a transmission system and tires of the same vehicle are changed little, when the unknown total vehicle mass of the vehicle is detected in a road test, the maximum corrected engine torque Mb2 is set to be multiplied by Mb1, the maximum corrected engine torque Mb2 is selected in a range of 0.92-1, and the smaller the interval period between the detection working condition and the calibration is, the smaller the interval period is, and the smaller the interval period is.

When the vehicle is loaded and the whole vehicle quality G2 road test detection working condition is unknown, a gear box specified gear which is the same as the calibration working condition is hung, an accelerator pedal is stepped to the rated power position and is stabilized, and the vehicle is suspended in the neutral gear to slide until the rotating speed of an engine exceeds the rated torque rotating speed nm. During acceleration, the detector measures the maximum acceleration A2 and the road surface gradient angle beta 2 in the advancing direction of the vehicle, and detects the deceleration a2 corresponding to the vehicle speed of A2 in neutral coasting, so that an engine torque balance equation of a standard environment state can be obtained: x Mb1 ═ Mj2+ Mf2+ (Fc2+ Fg2 ± Fz2) × R/(i × io)]X b2, wherein: mb1 is the calibrated corrected engine maximum torque in Nm; mj2 is engine inertia torque in Nm for the detected working condition; mf2 is engine accessory loss torque in Nm; fc2 is the net driving force of the driving wheels, Fc2 is (G2+ mc) x a2, G2 is the unknown mass of the entire vehicle in kg, mc is the equivalent inertia of the rotating parts of the drive train in kg, which is the fixed value of the vehicle, a2 is the maximum acceleration of the vehicle during acceleration in m/s²(ii) a Fg2 is the loaded driveline resistance for acceleration conditions; fz2 represents the slip-down force or the uphill resistance of the vehicle on a slope, and Fz2 is (G2+ mc) × G × sinBeta 2, g is gravity acceleration, a negative sign is taken when the slope goes down, a positive sign is taken when the slope goes up, and the unit is N; r is the rolling radius of the wheel in m; i is the transmission ratio of the specified gear of the gearbox, and io is the main transmission ratio; b2 is the power correction factor. The OBD may be installed only without measuring the road slope angle and the downhill or uphill resistance Fz2 on a straight road surface equals 0. The rolling resistance coefficient and the air resistance coefficient of the wheels or the running resistance coefficient of the same vehicle under the reference environment temperature states of different vehicle masses can be set to be unchanged, and free sliding is not needed. The power correction factor can be simply set to 1, mc can be set to 0 for larger vehicles, and Mf2 can be set to 0 when Mb1 is the corrected engine maximum output net torque without engine accessory loss torque.

From an engine torque balance equation of a standard environment state and a calculation formula of each parameter, except that the whole vehicle mass G2 is an unknown number of a primary term, other parameters are known detection values or test statistical values, and the whole vehicle mass G2 can be calculated.

The method for detecting the whole vehicle mass by the road test is a method for detecting the whole vehicle mass by the road test by installing a detector of a multidimensional acceleration sensor or installing an OBD or installing the detector and the OBD on a vehicle, and is characterized in that: firstly, calibrating the maximum torque Mb1 of the corrected engine of the vehicle by adopting a road test or a bench test, or simplifying the calibration Mb1 to be the maximum net output torque of the corrected engine without comprising the loss torque of accessories of the engine; in a certain period after calibration, the technical conditions of an engine, a transmission system and tires of the same vehicle are changed very little, the maximum torque Mb2 of a corrected engine of the vehicle is set to be multiplied by Mb1, the selection is carried out within the range of 0.92-1, the mass G2 of the whole vehicle is unknown after the vehicle is loaded, after a gear box is set in a running detection working condition, an accelerator pedal is stepped to a rated power position and is stabilized until the rotating speed of the engine exceeds the rated torque and rotating speed nm, the neutral gear is engaged for free sliding, or when different vehicle masses of the same vehicle are set, the rolling resistance coefficient and the air resistance coefficient of the wheels or the running resistance coefficient of the same vehicle in a reference environment temperature state are approximately unchanged, and the neutral gear sliding is not needed; according to an engine torque balance equation for detecting the working condition standard environment state, the balance equation is not known except that the whole vehicle mass G2 is unknown, and other parameters are known detection values or test statistical values, the whole vehicle mass G2 can be obtained through calculation, or only the OBD is installed, the road gradient is not measured, the sliding force or the uphill resistance of the vehicle on a ramp is set to be 0, or the power correction coefficient b2 is set to be 0, or the equivalent inertia of the neutral gear transmission system is set to be 0. Has the following technical advantages.

1. The device has good operability, can be detected in the starting and accelerating process after the truck is loaded, has good safety due to the low speed of the vehicle which is detected when the 1-gear or 2-gear low-speed gear is engaged, accords with the normal running operation, has lower rated torque and rotating speed of the diesel engine, can exceed the rated torque and rotating speed at low speed, can simplify the operation and does not need neutral sliding.

2. The device not only can detect the quality of the whole vehicle to prevent overload, but also can detect the dynamic technical condition of the engine, and can also detect the average braking deceleration fully sent out by low-speed braking after the truck is loaded, thereby being beneficial to ensuring the braking safety of the vehicle.

3. The accuracy of the equipment and the method can be checked by adopting a simple weighing mode, and the quality of the whole vehicle detected each time can be transmitted to a company and a supervision department by adopting a vehicle networking mode to be used as an effective technical means and a tool for efficiently managing overload.

Detailed Description

The specific implementation mode of the method for detecting the vehicle mass of the whole vehicle by the road test is described by calibrating and detecting the road test of a small vehicle in the starting and accelerating processes. The vehicle is provided with a multi-dimensional acceleration sensor detector and an OBD, wherein the rated torque Mm of an engine is 155Nm, the gear position of a gearbox is 1 gear, the gear ratio i of 1 gear is 3.933, the main gear ratio io is 3.769, the rolling radius of wheels is 0.307m, the weight G1 of the whole vehicle is 1441kg under a calibration working condition, and the equivalent inertia mc of a transmission system is 58 kg. The reference ambient temperature to is set to 20 ℃, the estimated Mf1 is 0.05 × Mm to 0.05 × 155 to 7.75Nm, and the corrected engine maximum torque Mb1 calibrated by the road test is 137.7 Nm.

The set relevant parameters of the detection working condition are the same as the calibrated parameters, the whole vehicle mass G2 is unknown after the loading mass, the accelerator pedal is stepped to the bottom for starting after the 1-gear of the gearbox is hung, and when the rotating speed of the engine exceeds the maximum torque rotating speed nm, the engine does not need to freely slide in a neutral gearAnd if the engine accessory loss torque Mf2 is equal to 1, the engine accessory loss torque Mf1 is equal to 7.75Nm, the detected working condition ambient temperature is 23.2 ℃, and the detected working condition road test vehicle maximum acceleration A2 is equal to 2.7454m/s²The engine inertia torque Mj2 is 24.324, the gradient sin beta 2 of the detection working condition on the downhill road surface is 0.01002, the power correction coefficient b2 is 1.008, and the engine torque balance equation under the standard environment state is as follows: x Mb1 ═ Mj2+ Mf2+ (Fc2+ Fg2-Fz2) x R/(i x io)]And x b2, obtaining (G2+ mc) 1722kg, G2-1722-58-1664 kg by solving, weighing the whole vehicle mass 1640kg under the weighing detection working condition on the weighing platform, wherein the error of the whole vehicle mass is (1664-1640)/1640-1.5%.

The ratio of the detected corrected engine maximum torque 137.7 to the specification rated torque 155 is 137.7/155-0.888-88.8%. This ratio reflects the technical state of the dynamics of the vehicle.

The method for detecting the whole vehicle mass of the vehicle through the road test has the advantages of simplicity in operation, good safety, low cost, simplicity in verification accuracy mode and the like, and the adoption of the road test mass of the Internet of vehicles is beneficial to controlling and monitoring the overload of the vehicle with high efficiency and low cost.

Claims

1. The method for detecting the whole vehicle mass by the road test is a method for detecting the whole vehicle mass by the road test by installing a detector of a multidimensional acceleration sensor or installing an OBD or installing the detector and the OBD on a vehicle, and is characterized in that: firstly, calibrating the maximum torque Mb1 of the corrected engine of the vehicle by adopting a road test or a bench test, or simplifying the calibration Mb1 to be the maximum net output torque of the corrected engine without comprising the loss torque of accessories of the engine; in a certain period after calibration, the technical conditions of an engine, a transmission system and tires of the same vehicle are changed very little, the maximum torque Mb2 of a corrected engine of the vehicle is set to be multiplied by Mb1, the selection is carried out within the range of 0.92-1, the mass G2 of the whole vehicle is unknown after the vehicle is loaded, after a gear box is set in a running detection working condition, an accelerator pedal is stepped to a rated power position and is stabilized until the rotating speed of the engine exceeds the rated torque and rotating speed nm, the neutral gear is engaged for free sliding, or when different vehicle masses of the same vehicle are set, the rolling resistance coefficient and the air resistance coefficient of the wheels or the running resistance coefficient of the same vehicle in a reference environment temperature state are approximately unchanged, and the neutral gear sliding is not needed; according to an engine torque balance equation for detecting the working condition standard environment state, the balance equation is not known except that the whole vehicle mass G2 is unknown, and other parameters are known detection values or test statistical values, the whole vehicle mass G2 can be obtained through calculation, or only the OBD is installed, the road gradient is not measured, the sliding force or the uphill resistance of the vehicle on a ramp is set to be 0, or the power correction coefficient b2 is set to be 0, or the equivalent inertia of the neutral gear transmission system is set to be 0.