A system is provided for controlling off-fall during trench excavation. The system includes a trench excavating assemblage. A mechanism moves the trench excavating assemblage from a position within a trench to be excavated to a position for dumping excavated material. A control system is configured to operate the trench excavating assemblage in an automated off-fall control mode to remove and/or compact off-fall along at least one edge of the trench.
An after-treatment system is provided, including an after-treatment module. The after-treatment module may include a housing configured to be installed in an exhaust system of an exhaust producing engine such that at least a portion of the exhaust from the engine flows through the housing. The housing may include at least one selective catalytic reduction (SCR) catalyst disposed within the housing and configured to facilitate a reduction reaction with NO.sub.x in the exhaust. In addition, the housing may include at least one NO.sub.x sensor disposed within the housing and configured to take measurements of an amount of NO.sub.x in the exhaust. Further, the housing may include a controller disposed on the housing and configured to receive the NO.sub.x measurements from the NO.sub.x sensor.
A hydraulic motor system for improved frequency response includes a hydraulic variator having a pump and a motor, wherein the pump includes a variable angle swash plate, and the system further includes an electric actuator for controlling an angle or torque of the swash plate, thereby controlling the motor output characteristics. The electric actuator for controlling the variable angle swash plate may comprise a linear electric motor, ball screw drive or a rotary electric motor. In an example, the rotary electric motor tilts the swash plate by applying a torque to the swash plate at a point away from its tilt axis. In a further example, the rotary electric motor tilts the swash plate via a worm drive or ball screw drive.
Engines that include different combustion strategies for different cylinders may create a power imbalance resulting in undesirable engine vibrations. The engine system of the present disclosure includes a first engine that is operable to produce a high NOx concentration exhaust and a second engine that is operable to produce a low NOx concentration exhaust. The first engine is fluidly connected to a first section of an exhaust passage and the second engine is fluidly connected to a second section of the exhaust passage. The exhaust from the first engine and the exhaust from the second engine are merged in a merged section of the exhaust passage downstream from both the first and second sections of the exhaust passages. The high NOx concentration exhaust may be converted to ammonia for reacting with the low NOx concentration exhaust to arrive at very low NOx concentration from the merged exhaust.
An exhaust system is provided having an exhaust path configured to direct an exhaust stream away from an engine. The system may also include an exhaust treatment device in the exhaust path and configured to act on one or more substances in the exhaust stream. Further, the system may include at least one temperature sensing device configured to provide an output indicative of a temperature at one or more locations on a working material of the exhaust treatment device. In addition, the system may include a controller configured to generate a temperature map of the working material of the exhaust treatment device and to determine deviations from an expected temperature map.