Vehicle Chassis Dynamoter
Vehicle Chassis Dynamoter Laboratory for optimisation of
- Powertrain- and engine efficiency
- Exhaust emissions
- Fuel consumption / -economy
There is an enormous international effort in the automotive industry to reduce fuel consumption and exhaust emissions to slow down global warming and ultimately to stop climate change. Many countries have already introduced stringent CO2 emission limits for passenger cars, additional to legislations that limit the amount of hazardous exhaust emissions, such as Carbon Monoxide (CO), Nitrous Oxides (NOx), Hydro Carbons (HC) and Particulate Matter (PM).
To help the industry in achieving these ambitious targets extensive research and testing is required. More efficient power trains offer the biggest potential in meeting these stringent and important requirements. Firstly novel technologies to improve power-train efficiency need to be conceived to reduce fuel consumption and emissions without negatively impacting other important vehicle attributes like performance (mainly power and torque), durability, drivability or noise/vibration harshness (NVH). In a second step simulation tools will help to verify the theoretical advantages and to optimises various design parameters. Thirdly the improvements of these new technologies need to verified with hardware in real tests. All of this needs to be achieved at minimal costs to enable rapid introduction into production on a wide scale. In the long term more deeper and fundamental research is required to discover new concepts and principals.
Deakin University is well position for this difficult task, which on the other hand is also a very exciting research opportunity. Just recently Deakin University has commissioned a new chassis roll dynamometer for measuring fuel economy, exhaust emissions and engine performance. This chassis dynamometer will enable the verification of new drive train and vehicle concepts. The equipment will also give students the chance to practically apply the knowledge learned in the newly developed related units, for example SEM714 Automotive Drive-Trains, SEM721 Automotive Product Development or SEM715 Chassis and Suspension, these units are also available for undergraduate students under the units SET401 and SET402 Advanced Topics in Engineering I and II. The equipment is used during laboratory practicals, final year projects, postgraduate projects or to support Deakin’s Formulae SAE racing team.
The laboratory complements several advanced software tools including a sophisticated simulation of internal combustion processes. Here a brief overview:
- Maximum test speed:240kph
- Rated. power at 200kph: over 500kW
- Rated torque: 1700Nm
- Fuel consumption measurement
- Exhaust emission analyser
- Recording of data from the Engine Control Module (ECU)
- Calibration and tuning of ECU parameters
- Interface for On-Board Diagnosis (OBD)
- Temperature measurements (more than 16 channels)
- Pressure measurements
- Cooling fan flow rate: 14,000 CFM
- Over 500 data channels can be measured and analysed
Figure 1 shows the advanced Chassis Dynamometer used for vehicle test. Typical tests that can be performed are steady state mapping tests, ramp tests, troubleshooting/diagnosis or simulation of emission drive cycles.
Figure 1: Chassis Dynamometer
Steady state mapping tests are performed to optimise the programmable engine management system and for tuning of relevant ECU parameters. Figure 2 shows an example of the main screen typically used for a mapping test. The dyno can control a predefined speed or load, alternatively the user can also control the speed and torque manually. Modifications of these ECU parameters are performed with a programmable calibration tool. This tool is also utilised to access relevant ECU parameters including comprehensive data acquisition.
Figure 2: Main screen
Ramp tests are another common task performed on any performance dyno. The 2 most common parameters analysed in this test are Power and Air Fuel Ratio (AFR), this enables the operator to see how rich or lean the vehicle is under full power and if some change needs to be performed. Figure 3 shows an example test report for a Ramp Test including Power and Air Fuel Ratio traces, it also shows the Maximum KW/HP and indicates at what road speed the maximum power was attained.
Figure 3: Ramp test result
Trouble shooting and diagnosis is becoming more and more important with the steady increase in complexity of vehicle powertrain systems. A typical analyse screen is shown in Figure 4. The unique character of the dynamometer is that it has the ability to give the user unparalleled Data Analysis of any Saved Test. The changing trends of some engine attributes, such as AFR, fuel consumption, emissions, manifold pressure and so on, can be analysed and presented various forms (figure 4). Through the OBD interface vehicle Diagnostic Trouble Codes (DTC) can be viewed.
Figure 4: A typical analyse screen
Emissions testing and measurement to analyse combustion efficiency and effectiveness is another advanced feature of the new laboratory. The dynamometer software includes the ability to perform drive cycle tests including standard legal drive cycles or user defined drive cycles. The emission analyser can analyse the following gases:
- CO (Carbon Monoxide)
- CO2 (Carbon Dioxide)
- HC (Hydrocarbons)
- O2 (Oxygen)
- NO (Nitrogen Monoxide)
- NOX (Nitrogen Oxides)
Figure 5: Emissions analyser