Testing method for predictive cruise control system of freight vehicles

Abstract

The test method for the predictive cruise control system of a freight vehicle is to solve the technical problem that the existing technology cannot test the fuel-saving effect of the predictive cruise control system of a vehicle on a multi-slope road on a flat closed road. The test method for the predictive cruise control system of a freight vehicle uses a standard closed test site for testing, and the actual driving information data of the vehicle is input into the software system to test the fuel consumption data. The key is to establish a set of test site maps that simulate uphill and downhill slopes based on the route of the standard closed test site in the software system, and divide the entire standard closed test site into several sections, which are provided with the length and angle of the uphill section, and the length and angle of the downhill section, to form a set of simulated test site maps with the same route but different surfaces. This solution can convert the slope into the weight of the vehicle by converting the vehicle mass equivalent, thereby achieving a comprehensive test of the predictive cruise control system of the reaction vehicle.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle testing technology and relates to a method for testing a predictive cruise control system of a freight vehicle. Specifically, the method can test the fuel-saving degree of the predictive cruise control system of the freight vehicle through equivalent conversion. Background Art

[0002] In recent years, with the continuous escalation of emission limits and fuel consumption requirements for commercial vehicles, more and more vehicle manufacturers have been installing or upgrading their vehicles with predictive cruise control systems. Predictive cruise control primarily replaces manual accelerator pedaling by providing automated, constant-speed driving for freight vehicles, thereby automatically controlling the throttle position and achieving cruise control. To a certain extent, the ability to maintain a certain constant speed not only reduces driver fatigue but also has a positive impact on vehicle energy consumption.

[0003] However, with the continuous improvement of fuel consumption standards, major automakers are claiming that their vehicles offer significant fuel-saving benefits. Currently, predictive cruise control systems are tested on relatively flat, closed test sites, which are considered ideal roads. As far as fuel efficiency is concerned, under ideal conditions, the fuel consumption of most manufacturers' vehicles is actually quite similar. Under ideal conditions, predictive cruise control systems appear to be only moderately effective. In fact, predictive cruise control systems are particularly effective on mountainous roads or roads with many slopes. If the manufacturer has configured the predictive cruise control system well, the fuel-saving effect on these roads will be significant. Otherwise, the fuel-saving effect may not be as good as that achieved by driver-controlled vehicle control. Therefore, if we want to evaluate the fuel-saving effect of predictive cruise control systems on mountainous roads or roads with many slopes, there is currently no better way to conduct testing. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem in the prior art that it is impossible to test the fuel-saving effect of a vehicle's predictive cruise control system on a multi-slope road on a flat closed road site. A testing method for the predictive cruise control system of a freight vehicle is designed. Through an equivalent conversion method, the vehicle weight is increased when going uphill and reduced when going downhill to simulate uphill and downhill, thereby achieving a fuel-saving effect test of the vehicle that is closer to that on real roads.

[0005] The technical solution adopted by the present invention is a testing method for a predictive cruise control system of a freight vehicle. The test is carried out in a standard closed test site, and the actual driving information data of the vehicle is input into the software system to test the fuel consumption data. The key is that, based on the route of the standard closed test site, a set of test site maps simulating uphill and downhill are established in the software system, and the entire standard closed test site is divided into several sections, wherein the length and angle of the uphill section, as well as the length and angle of the downhill section are provided, to form a set of simulation test site maps with the same route but different surfaces. On this basis, in the uphill section, the vehicle's own weight is added to the compensation weight as the vehicle weight input parameter when simulating uphill; in the downhill section, the vehicle's own weight is subtracted from the compensation weight as the vehicle weight input parameter when simulating downhill. The above vehicle weight input parameters are input into the software system to test a set of test fuel consumption data including a standard closed test site and multiple test sites simulating uphill and downhill.

[0006] The compensation weight is calculated based on the vehicle weight and the angle of the slope.

[0007] The actual driving information of the vehicle includes engine speed, engine torque, gear position of the transmission, throttle opening, brake pedal travel, tire pattern, tire model, vehicle speed, vehicle wind resistance, and vehicle weight.

[0008] The core technical solution of the present invention is to increase the vehicle weight when simulating an uphill vehicle and reduce the vehicle weight when simulating a downhill vehicle, and simulate the slope of the road by converting the vehicle weight into equivalent. Finally, the simulated test data with the slope and the test data of the actual standard closed test site are comprehensively analyzed to determine the fuel-saving effect of the vehicle's predictive cruise control system.

[0009] The beneficial effects of the present invention are:

[0010] By simulating road slopes through vehicle weight equivalent conversion, it is possible to simulate uneven slopes or mountain roads within a standard, enclosed area with a gentle slope, equivalent to testing in a closed area with a slope. This also allows for a more comprehensive test of the vehicle's predictive cruise control system, more closely resembling real-world road conditions, and providing a more accurate and realistic reflection of the system's performance. DETAILED DESCRIPTION

[0011] The scheme and effects of the present invention are described in detail below with reference to specific embodiments.

[0012] Assuming a vehicle weight of 40 tons and a length of 1,200 meters on a standard closed test site, the actual measurement can only reflect the fuel-saving effect of the predictive cruise control system when the vehicle is on a flat road, and cannot more truly reflect the fuel-saving effect of the vehicle when driving in actual road conditions.

[0013] In addition to the above tests, this solution also creates a set of test maps that simulate ramps in the software system.

[0014] Simulated slope test 1

[0015] The total length of this section is still 1,200 meters, but it is divided into four sections. The first 200 meters is a flat road, the middle 400 meters is an uphill section with a slope of 5%, the next section is a downhill section with a slope of 5% of 400 meters, and the last section is a flat road of 200 meters.

[0016] By setting different vehicle weight inputs at different locations or times, we can convert vehicle weight changes into road gradients. Based on the actual fuel consumption at each stage of the long straight road test at the proving ground, we can proportionally convert the fuel consumption for a 40-ton vehicle based on the vehicle weight at each stage.

[0017] Because a 5% slope is relatively small, sin (slope angle) and tan (slope angle) can be considered approximately equal. The compensation weight is 2 tons. For uphill sections, the vehicle mass input during the test is 40 + 40 × 5% = 42. Similarly, for downhill sections, the vehicle mass input is 40 - 40 × 5% = 38. This method can be used to convert vehicle mass equivalent to road slope.

[0018] Simulated slope test 2

[0019] The total length of this section is still 1,200 meters, divided into four sections. The first 200 meters is a flat road, the middle 400 meters is an uphill section with a slope of 10%, the next section is a downhill section with a slope of 10% of 400 meters, and the last section is a flat road of 200 meters.

[0020] This section simulates a 10% slope, and the test method is the same as simulated slope test 1. This test simulates a road with a relatively steep slope and determines the fuel-saving effect of the vehicle's predictive cruise control system on a 10% slope.

[0021] Of course, you can also set the slope to 15%, 20%, 25%, etc., to simulate the fuel saving effect of the predictive cruise control system on vehicles at different slopes. Since the principle is the same, I will not elaborate on it here.

[0022] From the above scheme, it can be seen that since there is no ramp in the actual test site, it is impossible to objectively and comprehensively reflect the fuel-saving effect of the vehicle's predictive cruise control system during the test. However, this scheme can convert the slope into the weight of the vehicle through vehicle mass equivalent conversion, thereby achieving a comprehensive test of the vehicle's predictive cruise control system.

Claims

1. The test method for the predictive cruise control system of a freight vehicle is conducted in a standard closed test site. The actual driving information data of the vehicle is input into the software system to test the fuel consumption data. The characteristics are: Based on the route of a standard closed test site, a set of test site maps simulating uphill and downhill sections is established in the software system. The entire standard closed test site is divided into several sections, with the length and angle of the uphill section and the length and angle of the downhill section set. This forms a set of simulated test site maps with the same route but different surfaces. On this basis, the vehicle's own weight plus the compensation weight are used as the vehicle weight input parameter for the uphill simulation. On downhill sections, the vehicle's own weight minus the compensation weight is used as the vehicle weight input parameter for simulating downhill driving. The above vehicle weight input parameters are input into the software system to test a set of test fuel consumption data including a standard closed test site and multiple test sites simulating uphill and downhill driving.

2. The method for testing a predictive cruise control system for a freight vehicle according to claim 1, wherein: The compensation weight is calculated based on the vehicle weight and the angle of the slope.

3. The method for testing a predictive cruise control system for a freight vehicle according to claim 1, wherein: The actual driving information of the vehicle includes engine speed, engine torque, gear position of the transmission, throttle opening, brake pedal travel, tire pattern, tire model, vehicle speed, vehicle wind resistance, and vehicle weight.