阅读说明：本技术 使用测功机进行测试的装置和方法 (Apparatus and method for testing using dynamometer ) 是由 利奥·阿方斯·杰勒德·布雷顿 于 2018-12-27 设计创作，主要内容包括：一种用于车辆动力系的测试方法,包括：在测功机上对第一车辆或第一车辆的一部分进行第一测试期间,协调地进行如下控制：(i)根据负载规范控制加速器踏板、加速器踏板信号、燃料喷射器、歧管压力、马达控制器或节流阀,以及(ii)根据速度规范控制测功机,使得所述测功机施加动态扭矩,该动态扭矩使得第一车辆或第一车辆的一部分的动力系产生动态动力系扭矩。所述测试方法还包括：记录定义所述动态扭矩的历史的值；以及在所述测功机或另一测功机上对第一车辆或第一车辆的一部分的第二测试期间,或在所述测功机或另一测功机上对第二车辆或第二车辆的一部分的第二测试期间,协调地进行如下控制：(iii)根据定义所述动态扭矩的历史的值控制加速器踏板、加速器踏板信号、燃料喷射器、歧管压力、马达控制器或节流阀,以及(iv)根据所述速度规范控制所述测功机或所述另一测功机,使得所述测功机或所述另一测功机施加动态扭矩,该动态扭矩使得第一车辆或第一车辆的一部分的动力系或第二车辆或第二车辆的一部分的动力系再现所述动态动力系扭矩。(A testing method for a vehicle powertrain, comprising: during a first test of a first vehicle or a part of a first vehicle on a dynamometer, the following controls are performed in coordination: (i) controlling an accelerator pedal, an accelerator pedal signal, a fuel injector, a manifold pressure, a motor controller, or a throttle valve in accordance with a load specification, and (ii) controlling a dynamometer in accordance with a speed specification such that the dynamometer applies a dynamic torque that causes a powertrain of the first vehicle or a portion of the first vehicle to produce a dynamic powertrain torque. The test method further comprises the following steps: recording values defining a history of the dynamic torque; and during a second test of the first vehicle or a part of the first vehicle on the dynamometer or another dynamometer, or of a second vehicle or a part of the second vehicle on the dynamometer or another dynamometer, the following controls are performed in coordination: (iii) (iii) controlling an accelerator pedal, an accelerator pedal signal, fuel injectors, manifold pressure, motor controller or throttle valve in accordance with values defining a history of said dynamic torque, and (iv) controlling said dynamometer or said another dynamometer in accordance with said speed specification such that said dynamometer or said another dynamometer applies a dynamic torque that causes a powertrain of the first vehicle or a portion thereof or a powertrain of the second vehicle or a portion thereof to reproduce said dynamic powertrain torque.)

1. A method of testing a vehicle powertrain, comprising:

during a first test of a first vehicle or a part of a first vehicle on a dynamometer, the following controls are performed in coordination: (i) controlling an accelerator pedal, an accelerator pedal signal, a fuel injector, a manifold pressure, a motor controller, or a throttle valve as a function of a load specification, and (ii) controlling the dynamometer as a function of a speed specification such that the dynamometer applies a dynamic torque that causes a powertrain of the first vehicle or a portion of the first vehicle to produce a dynamic powertrain torque;

recording values defining a history of the dynamic torque; and

during a second test of the first vehicle or a part of the first vehicle on the dynamometer or another dynamometer, or of a second vehicle or a part of the second vehicle on the dynamometer or another dynamometer, the following controls are carried out in coordination: (iii) (iii) controlling an accelerator pedal, an accelerator pedal signal, fuel injectors, manifold pressure, motor controller or throttle valve in dependence on values defining a history of said dynamic torque, and (iv) controlling said dynamometer or said another dynamometer in dependence on said speed specification such that the dynamometer or said another dynamometer applies a dynamic torque which causes the powertrain of the first vehicle or a portion thereof or of the second vehicle or a portion thereof to reproduce said dynamic powertrain torque.

2. The testing method of claim 1, further comprising: during the first test, exhaust back pressure, intake air humidity, intake air pressure, or intake air temperature is further controlled in coordination according to ambient air specifications.

3. The test method of claim 1, further comprising during the second test, further coordinately controlling exhaust back pressure, intake air humidity, intake air pressure, or intake air temperature in accordance with an ambient air specification different from an ambient air specification used during the first test.

4. The testing method of claim 1, further comprising: changing a calibration of the first vehicle or a portion of the first vehicle prior to performing the second test.

5. The test method of claim 4, wherein the calibration is an exhaust aftertreatment calibration or a powertrain calibration.

6. The testing method of claim 1, further comprising: changing exhaust aftertreatment of the first vehicle or a portion of the first vehicle prior to performing the second test.

7. The testing method of claim 1, further comprising: altering the first vehicle or a portion of the first vehicle prior to conducting the second test.

8. The testing method of claim 1, further comprising: perturbing the position of the accelerator pedal or the position of the brake pedal during the second test.

9. A method of testing a vehicle powertrain, comprising:

during a first test of a first vehicle on a dynamic powertrain torque drive road,

recording values of vehicle parameters indicative of the dynamic powertrain torque or indicative of dynamic drive torque requests to define a load specification, an

Recording vehicle speed or engine speed to define a speed specification;

during a second test of the first vehicle or a part of the first vehicle on the dynamometer machine or during a second test of the second vehicle or a part of the second vehicle on the dynamometer machine, the following controls are performed in coordination: (i) controlling an accelerator pedal, an accelerator pedal signal, a fuel injector, an associated manifold, a motor controller, or a throttle valve in accordance with the load specification, and (ii) controlling the dynamometer in accordance with the speed specification such that the dynamometer applies a dynamic torque that causes a powertrain of the first vehicle or a portion thereof or a powertrain of the second vehicle or a portion thereof to reproduce the dynamic powertrain torque; and

recording a value defining a history of the dynamic torque.

10. The testing method of claim 9, further comprising: during a third test of the first vehicle or a part of the first vehicle on the dynamometer or another dynamometer, or of a second vehicle or a part of the second vehicle on the dynamometer or another dynamometer, the following controls are performed in coordination: (iii) (iii) controlling an accelerator pedal, an accelerator pedal signal, a fuel injector, an associated manifold, a motor controller or a throttle valve in dependence on a value defining a history of said dynamic torque, and (iv) controlling said dynamometer or said another dynamometer in dependence on said speed specification such that said dynamometer or said another dynamometer applies a dynamic torque which causes the powertrain of the first vehicle or a portion thereof or of the second vehicle or a portion thereof to again reproduce said dynamic powertrain torque.

11. The testing method of claim 9, further comprising:

recording ambient air humidity, ambient air temperature, or atmospheric pressure during the first test to define an ambient air specification; and

during the second test, exhaust back pressure, intake air humidity, intake air pressure, or intake air temperature is further controlled in coordination according to the ambient air specification.

12. The testing method of claim 9, further comprising:

recording a parameter indicative of exhaust emissions, fuel economy, or powertrain efficiency during the first test and the second test; and

the parameters from the first test are compared to the parameters from the second test.

13. The testing method of claim 9, further comprising:

during a third test of the first vehicle or a portion of the first vehicle on the dynamometer or the other dynamometer, or during a third test of the second vehicle or a portion of the second vehicle on the dynamometer or the other dynamometer, further controlling exhaust back pressure, intake air humidity, intake air pressure, or intake air temperature in coordination with the same ambient air specification or a different ambient air specification used during the second test.

14. The testing method of claim 10, further comprising: changing the calibration of the first vehicle or a portion of the first vehicle or the calibration of the second vehicle or a portion of the second vehicle prior to performing the third test.

15. The test method of claim 14, wherein the calibration is a powertrain calibration.

16. The testing method of claim 10, further comprising: changing an exhaust aftertreatment or exhaust aftertreatment calibration of the second vehicle or a portion of the second vehicle prior to performing the third test.

17. The testing method of claim 10, further comprising: altering the second vehicle or a portion of the second vehicle prior to conducting the third test.

18. The testing method of claim 10, further comprising: perturbing the position of the accelerator pedal or the position of the brake pedal during the third test.

Background

The present disclosure relates to the technical field of automotive exhaust emission measurement and analysis and vehicle energy efficiency measurement. More specifically, the present disclosure relates to the field of predicting exhaust emissions of vehicles having an Internal Combustion Engine (ICE), including emissions from Hybrid Electric Vehicles (HEVs), based on simulating real-world conditions during laboratory testing, and predicting energy efficiency of vehicles of all powertrain types operating in the real world.

Modern automobiles with ICE may operate reliably under almost any combination of environmental, road grade, and driving conditions found on earth. Such vehicles are common throughout the world and operate regularly and reliably in ambient temperature ranges from well below 0 ℃ to above 40 ℃, from dry desert conditions to wet rainforests, and in highway operation from slow urban traffic from the front to the rear to german highways.

Many countries that own large numbers of automobiles have exhaust emission standards, i.e., the "tailpipe" standards that automobile manufacturers must comply with. Experience has shown that it is difficult and expensive to test vehicles under a wide range of real world environmental, road and driving conditions known to affect emissions and fuel economy of vehicles in the real world. And it is well known that the energy efficiency of HEVs and the range of single charge BEVs decrease at lower ambient temperatures.

Laboratory-based tailpipe emissions testing has historically been conducted over a limited range of environmental conditions, vehicle speed patterns, and driving conditions. As the number of vehicles has increased dramatically worldwide in recent years, and as vehicles have become more and more computer controlled, there is a need for governments and automobile manufacturers to better understand the emissions of vehicles under a wider range of operating conditions in order to continue to meet the National Ambient Air Quality (NAAQ) standard in the current "on-spec" of ambient air, and ultimately in the current "off-spec" of ambient air. Vehicle manufacturers must also be able to assess the impact of changing vehicle emissions control and powertrain calibration over a wider range of environmental and operating conditions.

New vehicle exhaust emission regulations are driven in part by measured levels of NAAQ, which are directed to specific standard pollutants known to directly or indirectly affect human health and to control greenhouse gas emissions. NAAQ levels vary widely around the world, depending on mobile emissions sources and stationary pollution sources. Population density, weather conditions, vehicle emissions performance, age and composition of local fleet vehicles, stationary air pollution sources, and geographic features are all factors that affect NAAQ. For example, air quality in southern california may be particularly poor due to high population density, coupled with well known temperature reversals due to geographic features and atmospheric conditions.

Automobiles and trucks with ICEs contribute to the overall pollution of "mobile sources", most notably "tailpipe emissions". While BEVs cause "stationary sources of pollution," i.e., emissions from power plants. Tailpipe emissions and energy efficiency of any particular vehicle operating in the real world depend on many factors, including various environmental conditions, road grade, driver behavior, traffic conditions, and the effectiveness of vehicle emissions control in relation to these factors.

If BEVs are produced in increasing numbers, they may become a significant factor in the future in the overall pollution from "fixed sources" as they draw energy from the grid. Therefore, it is also important to understand the energy efficiency of BEVs in real-world driving.

Because laboratory-based testing is repeatable, and because mass-based real-world (e.g., on-road) testing has not been possible until recently, i.e., since the commercialization of Portable Emission Measurement Systems (PEMS), new emission standards have been promulgated to control pollutant and greenhouse gas emission standards for vehicles with ICE, traditionally coupled with laboratory-based testing regimes and related methods.

While laboratory testing methods are known to be very accurate and repeatable for emissions measurements under actual test conditions, real-world driving can subject vehicles to a wide range of conditions that traditional laboratory testing protocols do not. The reasons for this phenomenon are many, including the difficulty in simulating the entire range of real-world temperature and barometric conditions in a laboratory, the effects of real-world driver behavior in real traffic conditions, etc.

To address the limitations of laboratory-only testing mechanisms for ICE vehicles, PEMS devices and methods have been developed for accurate real-world testing of exhaust mass emissions and fuel economy from a mobile vehicle while the mobile vehicle is driving in the real world. This is becoming increasingly important in understanding vehicle emissions that affect NAAQ, greenhouse gas emissions, and vehicle fuel economy.

PEMS has become a widely used commercial product by regulatory agencies and automobile manufacturers over the past 20 years. For example, from 2017 onwards, PEMS-based real-world testing has become a required test method for the european union vehicle certification process. However, laboratory testing remains a valuable tool for vehicle manufacturers and regulatory agencies during vehicle development because the testing protocols produce very repeatable test results. For example, the impact of large and small changes to the vehicle or powertrain on tailpipe emissions can be accurately determined by repeated testing after such changes are introduced.

Disclosure of Invention

Here, particular embodiments may relate to accurate and repeatable exhaust quality emission testing for ICE vehicles (or portions thereof), and energy efficiency measurements for all vehicle types — measurements representative of real-world energy efficiency and tailpipe emissions, where applicable, for any vehicle/engine model, on any route, and over any set of environmental conditions of interest. More particularly, certain embodiments relate to an apparatus and method for measuring emissions and energy efficiency performance of a vehicle over a wide range of real-world driving conditions by conducting tests primarily in a laboratory. For example, a vehicle testing method may include: operating the vehicle and a dynamometer for providing road load to the vehicle in accordance with a real world vehicle throttle specification (schedule) and a real world speed specification, respectively, which define a real world driving cycle for the vehicle traveling on a road; capturing output torque data from the dynamometer resulting from operation; operating the vehicle and dynamometer in accordance with the output torque data and the real-world speed specification, respectively, to replicate the road load experienced by the vehicle during the real-world driving cycle; and operating the vehicle according to a real-world shift schedule that further defines the real-world driving cycle. Real-world emission data corresponding to real-world ambient conditions and road loads experienced by the vehicle during the real-world driving cycle may be captured. Real-world energy efficiency data corresponding to real-world ambient environmental conditions and road loads experienced by the vehicle during the real-world driving cycle may be captured. The simulated real-world emissions data may be captured along with the replicated road load experienced by the vehicle, and the replicated road load may be verified by comparing the simulated real-world emissions data to the real-world emissions data. The real-world energy efficiency data may be captured along with a replicated road load experienced by the vehicle, and the replicated road load may be verified by comparing the simulated real-world energy efficiency data to the real-world energy efficiency data. The vehicle testing method may also include operating the vehicle under simulated ambient conditions and capturing emissions data, or operating the vehicle under simulated ambient conditions and capturing energy efficiency data.

A vehicle testing laboratory is equipped with a conventional chassis dynamometer or a separate axle dynamometer for each vehicle drive wheel, as well as a set of mass emission sampling devices for testing the ICE vehicle (if applicable), and a set of supplemental testing devices for exposing the test vehicle to a set of environmental conditions of interest (e.g., ambient temperature, pressure, and humidity) at the time the vehicle is tested.

Prior to laboratory testing, the vehicle to be tested is driven over any route of interest in the real world under any desired environmental and traffic conditions. For example, researchers and regulatory agencies may be particularly interested in the transportation trunks of NAAQ "off-label areas". And cold weather fuel economy performance may be of particular interest to manufacturers of vehicle models that are more widely used by customers in colder climates.

During real-world driving, PEMS may optionally be installed on an ICE equipped vehicle to measure and record mass emissions in grams per mile or grams per horsepower-hour of braking, depending on the vehicle's regulatory emission certification requirements. In addition to the optional emissions data, ambient weather conditions and other test parameters that characterize the vehicle operation are recorded, including vehicle speed, accelerator pedal or throttle position, and brake pedal position or state (i.e., on/off) throughout the test period. For a manually variable speed vehicle, gear selection and clutch pedal position must also be recorded.

After the real world test on the desired route, the vehicle is then taken to a specially equipped laboratory and placed on the chassis dynamometer, or alternatively connected to the axle dynamometer (one dynamometer for each drive wheel), while the laboratory's mass emission sampling device (in the case of an ICE vehicle) measures the mass emissions and the set of supplemental testing devices are employed to provide the desired environmental conditions of interest during vehicle operation, i.e., the environmental conditions may be the same or different than those actually encountered during the real world test.

For the first laboratory test, the entire set of real world test conditions including driver interaction and environmental conditions were reproduced on the chassis dynamometer by controlling the dynamometer speed to replicate vehicle speed on the road, while accelerator pedal motion or throttle position and braking action are controlled to replicate driving and vehicle response on the road. Mass emissions or energy efficiency (depending on powertrain type) and dynamometer output (feedback) torque signals throughout the test are recorded in the normal manner.

If PEMS emission data or energy consumption is optionally collected during real world driving, it can be directly compared to laboratory emission or energy consumption data collected under the same conditions during laboratory testing to ensure that they are equal within an acceptable range. This optional "validation" process is used to record a high degree of confidence that both laboratory and real world measurements are correct and reproducible.

In addition to optional verification, the initial dynamometer test provides an entire torque output history representing the real-world wheel torque of the vehicle under test, which is a good approximation of the wheel torque that would be found for the same vehicle under a wide range of environmental conditions when the same vehicle is operated by the same driver under the same traffic conditions. This real-world torque history, obtained at the laboratory, is then used for "torque matching" in subsequent dynamometer tests conducted under different simulated ambient test conditions. Thus, the principle of "torque matching" enables accurate and precise simulation of real-world driving under any environmental condition of interest for the same vehicle, speed history, driver influence and traffic pattern.

"torque matching" also enables accurate and precise simulation of real-world drive after other powertrain modifications (such as powertrain calibration changes or catalytic converter precious metal loading) are made, and measures the impact of such modifications on vehicle emissions or energy efficiency performance for any modifications that do not significantly affect vehicle road loading.

It will be appreciated that direct measurement of on-road torque and subsequent "torque matching" in the laboratory is optional, but requires more work to prepare the vehicle for testing. For example, a dedicated "torque wheel" that provides an output torque signal may be installed on the vehicle in place of the ordinary wheel.

After the first laboratory test, environmental conditions, powertrain calibration, emissions control changes, or other powertrain modifications may be made and the test re-run by controlling the accelerator pedal and brake pedal to reproduce or "match" the torque signal obtained from the on-road torque measurement or recorded dynamometer torque signal obtained during the dynamometer "validation" test.

Additional tests employing "torque matching" may be performed under many different environmental conditions and powertrain variations as required to fully characterize the emissions characteristics or energy efficiency of the test vehicle or powertrain over a wide range of environmental conditions and powertrain configurations as required.

Drawings

FIG. 1 illustrates various vehicle, driving, and traffic conditions that affect the emissions and/or energy efficiency of a vehicle.

FIG. 2 illustrates a vehicle being tested in the real world for obtaining a set of measurements sufficient to reproduce the test in a test laboratory and optionally collect actual on-road emissions and/or energy efficiency data.

FIG. 3 shows how dynamometer torque is obtained for subsequent laboratory testing purposes and how optional "validation" tests are performed using the environmental chamber.

FIG. 4 shows a test setup for simulating real world driving and collecting simulated real world emissions data from a vehicle using a chassis dynamometer within an environmental chamber.

FIG. 5 shows how dynamometer torque is obtained for subsequent laboratory testing purposes, and how an optional "validation" test is performed using an environmental condition simulator instead of an environmental chamber.

FIG. 6 shows a test setup for simulating real world driving and collecting simulated real world emissions data from a vehicle using an environmental condition simulator.

FIG. 7 shows how dynamometer torque is obtained for subsequent laboratory testing purposes, and how an optional "validation" test is performed using the axle dynamometer.

FIG. 8 shows a test setup for simulating real world driving and collecting simulated real world emission data from a vehicle using an axle mounted dynamometer.

FIG. 9 is a flow chart illustrating an exemplary overall process or testing method.

Detailed Description

Various embodiments of the present disclosure are described herein. However, the disclosed embodiments are merely exemplary, and other embodiments may take various and alternative forms not explicitly illustrated or described. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As one of ordinary skill in the art will appreciate, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combination of features shown provides a representative embodiment for a typical application. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

The use of PEMS has clearly shown that current laboratory-based testing protocols are generally unable to accurately characterize the emissions performance or energy efficiency (fuel economy) of vehicles operating in the real world and over a wide range of relevant factors listed above, due to the high cost and significant effort required to conduct representative laboratory tests. Similar test limitations of BEVs exist, limiting a comprehensive understanding of the energy efficiency of those vehicles operating in the real world under real world driving conditions and at lower ambient temperatures.

In some examples, an apparatus and method are designed for collecting accurate real-world emissions and energy efficiency test data for any vehicle in an accurate and repeatable manner over a wide range of environmental conditions that are not typically reproduced in a laboratory environment. The following description shows how a test laboratory may be used to accurately simulate real-world conditions for any combination of any vehicle and desired environmental conditions. In this manner, compliance with emissions and energy efficiency standards may be ensured by regulatory agencies, and the impact of changing the powertrain or powertrain calibration of a vehicle may be accurately determined by the automotive manufacturer to effectively achieve emissions compliance and maximize its fuel economy to its customers.

The test method described above may employ other vehicle operating parameters as an alternative to using throttle position and/or using torque to control a dynamometer in real world driving. For example, the fuel flow rate, fuel injector pulse width, and powertrain computer calculations used to calculate powertrain torque during vehicle operation are similar to throttle position or torque for subsequent vehicle or dynamometer control under the same real or simulated environmental conditions used for laboratory testing.