Solid-state switch separates subsystems in autonomous cars

October 11, 2017 // By Christoph Hammerschmidt
Automotive supplier Eberspächer Controls has developed intelligent switching systems for the safe disconnection and connection of the complex wiring systems of autonomous vehicles. The Autonomous Driving Safety Switch is intended for 12-volt on-board networks with at least two batteries. In fully automated vehicles, the Battery and Boardnet Safety Module additionally ensures intelligent power distribution and reliable supply of safety-relevant components.

The vehicles of the future will not only have several batteries, but also several on-board systems. The new products from Eberspächer Controls ensure their safe connection and separation. The first vehicles that comply with the SAE J3016 standard (SAE J3016) automation level 3 have recently gone into series production. Here, the driver is required to intervene in certain situations, but he does not have to monitor the system continuously. This is made possible by the Autonomous Driving Safety Switch (ADSS) from Eberspächer. The bi-directional disconnector is used in 12-volt on-board networks with at least two batteries for level 3 or 4 of the autonomous driving - depending on the number of safety-relevant loads in up to 20-fold implementation. In the event of over- or undervoltage, it disconnects the two sub-networks and thus secures safety-relevant functions such as brakes and electrical steering aids. It has an integrated overcurrent detection and is designed for ASIL Level B or ASIL Level D, depending on customer-specific requirements. The latter level covers the highest security requirements for development, testing, documentation and function. 

Eberspächer also offers a solution for fully-automated cars with high-voltage low-voltage wiring systems: The Battery and Boardnet Safety Module (BBSM) is tailored to the requirements of vehicles at the future SAE level 5, in which no human intervention and therefore no driver is required. BBSM offers intelligent power distribution and reliable supply of safety-relevant components in fully redundant on-board networks. In the event of a fault, the system separates the high-voltage DC/DC converter from the 12-volt on-board power supply within a maximum of 100 microseconds. In addition to the lithium battery, it thus protects safety-relevant loads such as actuators, sensors and the central control unit. The BBSM consists of several battery and on-board circuit breakers and a combination of microcontroller and system basic chip classified according to ASIL D. The electronics experts develop the complex control software individually for each customer.

More information: www.eberspaecher.com