A current focus for Japanese automaker Honda R&D Co., Ltd (Honda) is on advancing the development of what are called idling stop systems.
Working in association with Siemens PLM Software, Honda is developing solutions to reduce unwanted NVH (Noise, Vibration, Harshness).
Japanese automaker Honda R&D Co., Ltd (Honda) is among the leading developers of hybrid vehicles. A current focus for the company is on advancing the development of what are known as idling stop systems. These systems are what cause the vehicle engine to automatically cut out when at a standstill, for instance at red lights, and restart when it's time to drive off. Consumers outside of Europe have been slow to buy into the concept due to the vibrations and brief interruptions to music caused when the car restarts. Honda is working with Siemens PLM Software to develop quieter alternatives with fewer vibrations, which not only reduce fuel consumption and emissions but also help to cut down on noise pollution in cities. Using the Siemens software, Honda has been able to develop precise models and simulations which supply valid data to help improve its idling stop systems.
Around 70 percent of all cars driven in Europe are already using idling stop systems which enable fuel consumption to be cut by up to 15 percent. These systems are far less widespread in the USA and other countries, where they are used in only seven percent of vehicles. This is due first and foremost to lack of acceptance by drivers for the brief interruptions to music and the sudden occurrence of noise when the vehicle restarts. Because the noise occurs unexpectedly and without active intervention by the driver, it's frequently considered an annoyance. Honda is among the Japanese OEMs (Original Equipment Manufacturers) working at full steam to investigate solutions which will improve the drive experience by reducing unwanted NVH (Noise, Vibration, Harshness) over which the driver has no influence. In its bid to become an early adopter of any new technology, Honda has opted to work with Simcenter Engineering services from Siemens PLM Software.
Improvement hinges on process understanding
Honda and Siemens have been partners for over 20 years, and this long and fruitful cooperative association provided the perfect basis for a successful outcome to this project. By using Simcenter, Honda was able to collate a large amount of data, particularly as regards NVH, with the aim of reducing vibrations and noise on restart when using idling stop systems. The solution they were seeking should not compromise engine performance, and so find greater acceptance among drivers. Using Simcenter Amesim software, Honda worked with Siemens to devise a method of predicting and evaluating engine vibrations. This allowed the restart process to be precisely mapped – starting with the vehicle control signals through to the cylinder pressure which results in driveline torque, released forces and ultimately body vibration shock. By allowing for the in-cylinder pressure deviation, Honda is now able to determine the part characteristics for engine restart vibrations during the design phase, and find ways of reducing them. "Thanks to our collaboration with the Simcenter Engineering team, our development cycle time is under better control," says a delighted Satoshi Watanabe, responsible for Model-Based Development at Honda.