Abstract: A working method using an AUV includes a step of working on a work object with a work device included in the AUV while causing the AUV to sail along the work object, a step of dropping and sinking a transponder to the bottom of water, a step of causing the AUV to sail toward a return destination, and a step of resuming work on the work object by causing the AUV to sail from a return destination to the vicinity of a work suspended position, at which work on the work object is suspended, based on information obtained by acoustic positioning using the transponder that is sunk to the bottom of water.

Abstract: A control method of an EGR system of an engine capable of effectively performing an EGR control at a time of rapid acceleration. For this purpose, an intake air flow rate of the engine is obtained, and from a target EGR valve opening degree and a difference in pressure in front of and behind the EGR valve, a virtual EGR gas flow rate is arithmetically operated. A virtual EGR rate is obtained from the intake air flow rate, the fuel flow rate and the virtual EGR gas flow rate, and a difference from or a ratio to a target EGR rate obtained from the engine speed and the fuel flow rate is obtained. A command EGR valve opening degree is obtained from an EGR valve opening degree correction coefficient obtained from the difference or the ratio, and the target EGR valve opening degree, whereby the EGR vale is driven.

Abstract: A control method of an EGR system of an engine capable of effectively performing an EGR control at a time of rapid acceleration. For this purpose, an intake air flow rate of the engine is obtained, and from a target EGR valve opening degree and a difference in pressure in front of and behind the EGR valve, a virtual EGR gas flow rate is arithmetically operated. A virtual EGR rate is obtained from the intake air flow rate, the fuel flow rate and the virtual EGR gas flow rate, and a difference from or a ratio to a target EGR rate obtained from the engine speed and the fuel flow rate is obtained. A command EGR valve opening degree is obtained from an EGR valve opening degree correction coefficient obtained from the difference or the ratio, and the target EGR valve opening degree, whereby the EGR vale is driven.

Abstract: The present invention is a method of controlling a fuel injection apparatus for an internal combustion engine, and is capable of preventing the breakage of a component which is exposed to high-temperatures, such as an exhaust manifold. To this end, a first set temperature and a second set temperature, higher than the first set temperature, are set in advance, and a temperature of exhaust gas from an internal combustion engine (1) is detected. The number of occasions at which the temperature of the exhaust gas exceeds the first set temperature and the lengths of time during which the temperature of the exhaust gas has exceeded the second set temperature are totaled respectively, and either when the total number of occasions exceeds a predetermined number of occasions or when the total of the lengths of time exceeds a predetermined length, at least one of the following actions are taken: giving an alarm, reducing a fuel injection rate and changing the injection timing.