Tata Motors has secured a patent for its invention regarding an auto stop-start control system for manual transmission vehicles which provides fuel economy with minimal change in driver behaviour.
The desi auto firm claims that the objectives of the present invention are to provide an auto stop-start system for manual transmission vehicles in which an auto stop is prevented from occurring if the engine speed is above the idle speed, and to provide a simple and cost effective vehicle auto stop-start control system.
The company in the patent application submitted that the invention will be a solution to save the fuel wasted when idling at traffic signals by automatically switching off the engine when the vehicle is stopped.
According to a patent document filed by Tata Motors, the auto stop-start control system comprises an electronic controller and an engine starting and stopping system which can start or stop the engine in response to electronic commands.
The electronic controller will have an assembly of digital input blocks for measuring ignition key state, crank position, brake pedal state, clutch pedal state, engine speed and vehicle speed.
Granting the patent, Pinkesh K Jain, assistant controller of patents & designs, Mumbai patent office said: “Having considered the submissions and amendments, I find that amended claims are clearly disclosing the structural components involved in the claimed method. The claimed method involves interaction among the technical means to achieve the technical objective.”
The company submitted that various digital sensors like vehicle speed sensor, engine speed sensor, clutch pedal sensor and brake pedal sensor are interfaced with the digital inputs block of electronic controller and analog sensors like battery voltage sensor and coolant temperature sensor are connected with the analog inputs block of electronic controller. The electronic controller is then interfaced with the engine starting / stopping system.
The digital and analog information obtained by the electronic controller through the digital and analog inputs blocks respectively are first stored in the memory block. Using this stored information from the memory block, the semiconductor device does the necessary processing and accordingly generates the signals for starting or stopping the engine. The engine starting/stopping system starts or stops the engine in response to the said signals. After the vehicle comes to a complete stand-still, the electronic controller checks if the engine is running, if so, the controller checks if the engine speed is at idle speed, Tata Motors said.
In conventional auto stop-start control system for manual transmission vehicles the engine is switched off when the drives engages the neutral gear and release the clutch pedal. However, many drivers, especially in third world countries would like to keep the vehicle stationary while transmission is in gear and the clutch and brake pedals are pressed simultaneously.
The drawback associated with this system is that in such situations, the engine will not be turned off and the driver would get no benefit of the auto stop-start feature, the company said.