Abstract: Focusing laser beams are emitted to a gas plasma produced through discharge and a laser thermal plasma, which is independent of the gas plasma and extends coaxially along the laser beams, is produced in a gas flow space.

Abstract: The thermal load on a transmission clutch, which is generated when a shift between forward and reverse is made, can be reduced and a shock from a speed change can be eliminated. To these ends, as soon as a speed change signal is received (step 150), an all clutch control system (ACC) is actuated to set a target acceleration in terms of the amount of control (steps 152, 154). Then, it is determined whether the speed change involves a shift between forward and reverse (FR speed change) (step 156). If the speed change is found to be the FR speed change, then it is further determined whether the vehicle speed V is larger than a reference value V.sub.O (step 158); if the vehicle speed is larger than the reference value, then the oil pressure for operating a steering brake is read from preestablished map data (step 160), and the steering brake is operated by the oil pressure which has been read (steps 162, 164). After that, the ACC control program goes back to step 156.