A method for controlling depressurization of a fuel system mounted on board of a vehicle including a vehicle impact sensor, the method including: detecting, using the vehicle impact sensor, whether an impact on the vehicle is present; and when the impact on the vehicle is detected, using a controller for generating at least one signal for controlling an opening of at least one valve disposed in the fuel system, to release internal pressure of the fuel system.

Methods and systems are described for detecting valve actuation faults in internal combustion engines operating in a skip fire operational mode. In one aspect, for each skip fire working cycle, an expected exhaust pressure is determined for a time period corresponding to a potential exhaust event. One or more exhaust gas pressure sensors are then used to measure an actual exhaust pressure during the potential exhaust period. The actual exhaust pressure is compared to the expected exhaust pressure to determine whether a valve actuation fault has occurred. A variety of valve actuation faults can be identified using the described approach. In some embodiments pressure sensors are deployed in the runners of the exhaust manifold.

A valve motion measurement assembly is provided for a cylinder valve of an internal combustion engine provided with a valve stem and with a valve head. The valve motion measurement assembly includes a valve position sensor, a supporting bracket provided with at least one sensor seat for the valve position sensor, and a sensor target element configured to be coupled to the valve stem at a distance from the valve head to follow the motion of the cylinder valve. The valve position sensor interacts with the sensor target element for determining the position of the cylinder valve.

Methods and systems are described for detecting valve actuation faults in internal combustion engines operating in a skip fire operational mode. In one aspect, a torque model is used to estimate an expected net torque during a selected operating window. The torque model considers an expected torque contribution from each of the cylinders and accounts for the effects of specific skip fire firing decisions that affect the expected torque contribution from each cylinder. A parameter indicative of the actual engine torque is also measured. Valve actuation faults can then be identified based at least in part on a comparison of the measured parameter to an expected parameter value that is based at least in part on the expected net torque. With the described approaches, the occurrence of the valve actuation fault can be made within one engine cycle of the initial occurrence of the fault.

A bi-directional tractor exhaust system with ground speed detection includes a downwardly directed exhaust pipe, an upwardly directed exhaust pipe, and an intermediate exhaust pipe connected to the outlet of a diesel particulate filter. An exhaust pipe valve may be opened or closed by an actuator to direct exhaust through the downwardly directed exhaust pipe during regeneration of the diesel particulate filter if a signal from a ground speed sensor indicates ground speed above a first speed, or through the upwardly directed exhaust pipe if the ground speed is below a second speed.

A hydrogen-oxygen cycle engine. The hydrogen-oxygen cycle engine comprises a cylinder assembly, a hydrogen supply assembly, an oxygen supply assembly, a cycling medium assembly, an atomized water assembly, a condensate water recovery assembly and a control system. Said engine has the advantages of reasonable structural design, high automation degree, no carbon emission, etc., and can thoroughly solve the problem of environmental pollution. Also provided is a using method for the engine.