Mazda Motor Corporation

Yazaki Corporation

The Furukawa Electric Co., Ltd.

Hideki Nakazono

Yoshikazu Nobutoki

Koji Terayama

Osamu Michihira

Yutaka Matsuda

Seiji Hirano

Kyosuke Hashimoto

Masaaki Shimizu

Hiroaki Sakamoto

Hiroo Moriue

Nozomi Kawasaki

Toshitaka Hara

Toshiyuki Matsuzaki

Mitsuru Anma

Kouji Umegaki

A vehicle multiplex transmission apparatus which can operate all the auxiliary units of a vehicle even when a power supply line of the vehicle is locally short-circuited. This vehicle multiplex transmission apparatus includes a plurality of control nodes arranged in respective portions of a vehicle, for controlling vehicle auxiliary units, and a multiplex transmission line for connecting among the plurality of control nodes. The control nodes are connected to a power supply node arranged at a predetermined position of a vehicle body through two independent systems of first and second power supply lines. The first power supply line supplies power to vehicle travel auxiliary units. The second power supply line supplies power to general system auxiliary units, but it can supply power to the travel auxiliary units as needed.

Vehicle multiplex transmission apparatus

When a message is transmitted, frame by frame, from any one (10) of a plurality of multiplex nodes to a common multiplex bus (MB) to which the multiplex nodes are connected, each of the multiplex nodes (20 and 30) determines that transmission of a frame therefrom is allowed when it detects a transmission permission signal (b, b') added to the frame after detection of and idle state of the multiplex bus, and starts transmitting a message data frame. This makes it possible to properly implement priority-based control according to the priority levels of the data frames irrespectively of variations in the reference clocks of the multiplex nodes. Further, receiving multiplex nodes perform frame synchronization at the rise of a special code (a) of a start code (SOM) of a message data frame, and then perform re-synchronization at the rise of a special bit pattern (b') which includes a passive bit and a dominant bit. This prevents synchronization from being deviated and bit errors resulting from deviated synchronization, thus leading to higher reliability of multiplex transmission.

Multiplex transmission method and a synchronizing method in multiplex

Communication nodes which respectively transmit periodic information and non-periodic information in multiplex fashion are provided separately. These communication nodes selectively transmit periodic information to a multiplex transmission line which is originally for transmitting the non-periodic information or non-periodic information to a multiplex transmission line which is originally for transmitting the periodic information in accordance with the state of transmission/reception of the periodic information and non-periodic information.

Multiplex transmission apparatus

Growing community of inventors

Hiroshima, Japan

Hideki Nakazono