To mitigate greenhouse emission 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 catalyst monitoring on vehicles. It is imperative to upgrade engine management system for On-board diagnostics (OBD) that refers to a vehicles self-diagnostic and reporting ability. OBD systems enables owner of vehicles 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 not to exceed OBD thresholds. Consequently, the use of specific NOx emission control systems became necessary in BS VI OBD II B for 3-wheeler applications. Additionally, the performance and integrity of the catalytic converter must be monitored. Driver warnings, inducement requirements, and catalytic converter monitoring for NOx emission control systems are essential during the operation of 3-wheeled vehicles. The driver inducement requirements are designed to enforce and ensure the correct operation of the NOx control system, while catalyst monitoring ensures the performance and integrity of the catalytic converter.
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 a consumable fluid stored in a separate tank to reduce emissions. This includes monitoring for low fluid 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 MIL ON, EGR and NOx after-treatment system monitoring, particulate filter and catalytic converter monitoring. For the driver inducement system algorithms were designed for inputs 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 delta pressure sensor is added in the exhaust stream, which monitors the inlet and outlet pressure of the catalytic converter. This monitoring of inlet and outlet pressure confirms the integrity of the catalytic converter and detects malfunctions if any. This is novel concept for driver inducement requirements for NOx emission and catalyst monitoring control systems on Diesel three-wheel application as per BS VI OBD II B legislation.