Automated diagnostic systems

With the extremely advanced and complex design of modern vehicles, their high power and torque, it is necessary to employ advanced diagnostic systems. Quick detection and diagnosis of all defects will protect the vehicle against more serious failures, and will prevent excessive fuel consumption and harmful emissions, as well as prevent the reduction of the efficiency and functionality of vehicles. The mechatronic vehicle diagnostic system must include the diagnostic modules for the following components: engine, powertrain, steering, brake system, suspension and electrical equipment. The study discusses the hardware and software components of the mechatronic vehicle diagnostic system, and presents the sample sensors installed in the vehicle to monitor the parameters of components included in the diagnostic system. The vehicle diagnostics system has been presented using the example of diagnostics of wheeled tractors. For this purpose, two alternative diagnostic devices have been developed: a prototype MSDC-1 device, and a production version of the MSDC-2 device. Following a minor adaptation, both devices can be used in the diagnostics of other wheeled vehicles powered by I.C. engine. In further paragraphs of the study, some of the field tests performed on the diagnostic units are discussed. The study also presents some of the test results in the form of diagrams of changes in the temperature of specific engine components. In the diagrams illustrating the results of the tests, the changes of specific operating parameters of the wheeled tractor over time during tests of the MSDC-1 and MSDC-2 units can be observed. The devices differ significantly in terms of design, but they share a purpose, namely online diagnostics of vehicle condition

Metoda wyznaczania efektywnych obwodów toczenia kół pojazdów

Determining the exact values of the rolling radii of the wheels is extremely important in terms of the functioning of the safety systems of modern vehicles. It is on the basis of the rotational speed of the vehicle wheels that the traction parameters of the vehicle are determined, as well as the warning about the existence of low tire pressure. The precision of determining the turning radius significantly improves the accuracy of calculations of the slip value, driving force, and also plays a key role in determining the linear speed of a motor vehicle. This article presents the method of determining the value of the rolling radius of a tire and tests of changes in its value under the influence of changes in the value of vertical load and tire pressure. Based on the performed measurements, a mathematical model of changes in the value of the effective wheel rolling circumference from the above-mentioned parameters was determined. The results of the regression analysis indicate a very good fit of the developed model to the results of the conducted experimental research.Określenie dokładnych wartości promieni toczenia kół jest niezwykle istotne w aspekcie funkcjonowania systemów bezpieczeństwa nowoczesnych pojazdów. To na podstawie prędkości obrotowych kół pojazdu określane są parametry trakcyjne pojazdu, jak również generowane jest ostrzeżenie o byt niskim ciśnieniu w ogumieniu. Precyzja określania promienia toczenia wpływa na znaczną poprawę dokładności obliczeń wartości poślizgu, siły napędowej, jak również odgrywa kluczową rolę w przypadku określania liniowej prędkości ruchu pojazdu samochodowego. W niniejszym artykule przedstawiono metodę wyznaczania wartości promienia toczenia koła ogumionego oraz przeprowadzono badania zmian jego wartości pod wpływem zmian wartości obciążenia pionowego oraz ciśnienia w ogumieniu. Na podstawie przeprowadzonych pomiarów, wyznaczono model matematyczny zmian wartości efektywnego obwodu toczenia koła od wymienionych parametrów. Wyniki analizy regresji wskazują na bardzo dobre dopasowanie opracowanego modelu do wyników przeprowadzonych badań eksperymentalnych

Conditions for optimizing powertrain performance in a vehicle with an internal combustion engine

The paper presents optimization of the drive system in terms of adapting it to the characteristics of another engine. Powertrain parameters in a vehicle with an internal combustion engine were selected based on the following criteria: fuel consumption, engine dynamics, and emission standards for harmful substances. A light-duty passenger vehicle with gross vehicle weight rating (GVWR) of 3.5 tons was modified by replacing a spark-ignition engine with a diesel engine. The gear ratio in the powertrain had to be modified accordingly to optimize the engine’s performance, enhance engine dynamics, minimize fuel consumption and toxic emissions. The optimization of selected parameters of the vehicle driveline was performed based on the requirements of the standard NEDC and WLTC cycles

Methodology for measuring car traction parameters

The article presents methodology for testing the traction parameters of the vehicle on the laboratory stand. The tests have been carried out using MAHA LPS 3000 chassis dynamometer. Power output can be measured in two ways, at steady state or during acceleration. Both have benefits as well as drawbacks. Car manufacturers are required to use steady state tests for certification of power output. It has an advantage as it is a well defined test that is easy to repeat and verify. The problem with results measured during acceleration is that the acceleration itself has a considerable effect on the result

Methodology for measuring car traction parameters

The article presents methodology for testing the traction parameters of the vehicle on the laboratory stand. The tests have been carried out using MAHA LPS 3000 chassis dynamometer. Power output can be measured in two ways, at steady state or during acceleration. Both have benefits as well as drawbacks. Car manufacturers are required to use steady state tests for certification of power output. It has an advantage as it is a well defined test that is easy to repeat and verify. The problem with results measured during acceleration is that the acceleration itself has a considerable effect on the result

Models of diagnostic relations in a wheeled tractor

Modern wheeled tractors are equipped with new-generation electric and electronic systemswhich control the operation of actuator systems. Such solutions require an on-board computer foronline monitoring of functional performance, exhaust gas emissions, safety and operating parameters.Mechatronic diagnostic systems identify the machine’s actual operating load in different operatingmodes and under specific circumstances.Knowledge engineering methods have not yet been developed in the process of diagnosing a tractor’sdefects, but they seem to offer almost endless possibilities. A defect is defined as every event whichhas an adverse effect on tractor performance and which should be detected in the diagnostic processwith an indication of the type and place of damage as well as the magnitude and variability of damageover time. Diagnostic knowledge is a symbolic representation of empirical relations based on whichdiagnostic procedures are developed.The identification of diagnostic relations based on different methods and information sources willfoster the growth of reliable declarative knowledge comprising facts and state-symptom diagnosticrelations, as well as procedural knowledge which underlies diagnostic inference.The determination of symptom-damage relations requires a knowledge base of potential defects in theassemblies and subassemblies of a wheeled tractor. A diagnostic knowledge base can be created based on the identified diagnostic relations, including data acquired during damage simulations.The identification of diagnostic relations between specific defects and the corresponding parameterswas one of the key steps in the process of developing a mechatronic diagnostic system in a wheeledtractor. To facilitate the detection of specific defects at a given moment, a single set of diagnosticsymptoms was allocated to every defect in a wheeled tractor. Diagnostic symptoms are identified bysensors when threshold values are exceeded.[b]Keywords[/b]: diagnostics, wheeled tractor, diagnostic relation