To mitigate greenhouse emissions such as carbon monoxide (CO), carbon dioxides (CO2), oxide of nitrogen (NOx) and particulate matter reduction Government of India implemented Bharat Stage VI (BS-VI) norms from year 2020. Moving to more stringent emission norms poses challenges for automakers in several ways such as meeting exhaust emissions, on board diagnostic, drivers’ inducement, and particulate filter monitoring on vehicle. It is imperative to upgrade engine management system for on-board diagnostics (OBD) that refers to a vehicles self-diagnostic and reporting ability. On board diagnostics systems enables owner of vehicle to gain access of the various vehicle sub-systems.
OBD-II standards were made more rigid, requiring the malfunction indicator lamp (MIL) to be activated if emission-related components fail. Also, vehicle emissions carbon monoxide (CO), oxide of nitrogen (NOx) and particulate matter not to exceed OBD thresholds. Consequently, the use of specific oxide of nitrogen (NOx) emission control systems became necessary in Bharat Stage VI for 3-wheeler applications. Additionally, the performance and integrity of the particulate filter must be monitored. Driver warnings, for water injection system, and particulate filter monitoring are essential during the operation of 3-wheeled vehicles to ensure correct operation of NOx emission control systems. The driver inducement requirements are designed to enforce and ensure the correct operation of the NOx control system, while particulate filter monitoring ensures the performance and integrity of the particulate filter.
Present study deals with 3-wheeled diesel vehicles having port water injection technology on engine. As per automotive Indian standard for three-wheeler category vehicles, BS VI emission norms must have systems in place to monitor for malfunctions related to water quantity if they rely on the use of water stored in a separate tank to reduce emissions. This includes monitoring for low water levels and empty tanks, as well as ensuring the proper functioning of the dosing or injection subsystem.
The driver inducement system must comply with water level indication, consumption monitoring, driver warning system, storage of failure information. Also, vehicle must comply with the OBD II-B requirements such as circuit continuity and rationality for all emission-related powertrain components, distance travelled since malfunction indication lamp glow, EGR and after-treatment system monitoring, For the driver inducement system algorithms were designed for input parameters which were captured from different sensor and actuators of engine and vehicle management system. These inputs were sent to the engine control unit (ECU), which processes the data and generates outputs to the water injector, display unit, diagnostic management system, warning lamps, buzzer, and instrument cluster. For particulate filter monitoring, a differential pressure sensor is added in the exhaust stream, which monitors the inlet and outlet pressure of the particulate filter. This monitoring of inlet and outlet pressure confirms the integrity of the particulate filter and detects malfunctions if any. This is novel concept for NOx emission control and catalyst monitoring control systems on diesel three-wheel vehicle application as per BS VI OBD II B legislation.