Mechanical, hydraulic, drivetrain, and automation technologies in excavators, bulldozers, and dump trucks.
This is an editorially selected reading order. Begin at step 1 or go directly to the topic you need.
A hydraulic excavator is a mobile robot that distributes the rotation of a diesel engine to hydraulic pumps, cylinders, and reduction gears. This article diagrams the kinematics of the boom, arm, and bucket, bucket-edge estimation via IMU, the planetary gears in the upper structure and undercarriage, current ICT/electrification efforts from Komatsu and Caterpillar, and ongoing research into autonomous excavation.
A bulldozer is a machine that unifies control of its earth-pushing blade and crawlers through hydraulics and the drivetrain. This article organizes ground pressure, traction force, blade attitude, GNSS/IMU-based ICT construction, the design thinking behind Komatsu's D61/D65 series and Caterpillar's D6 XE, and research into electrification and autonomous leveling — through both equations and a field perspective.
A wheel loader scoops earth using a combination of articulated steering, where the body itself bends in the middle, and a bucket driven by a Z-bar or parallel linkage. This article organizes the steering kinematics, the breakout force produced by the linkage, and the division of roles versus the hydraulic excavator and bulldozer, alongside Komatsu's current WA series.
A dump truck isn't just something that hauls earth — it's a machine that designs payload, tires/crawlers, diesel/electric drive, the hydraulic bed, braking, and mine autonomous haulage as a single transport system. This article covers payload calculation, grade resistance, retarders, and current autonomous haulage technology from Komatsu and Caterpillar.
Before it's 'a machine that lifts with great force,' a crane is 'a machine that doesn't tip over.' This article explains the differences among mobile cranes, crawler cranes, and tower cranes; the rated-load chart determined by boom and working radius; the tipping moment and stability margin at the outriggers; and how the overload-prevention device works — alongside current machines from Kobelco, Tadano, and Liebherr.
Compaction equipment applies repeated loading to soil or paving material, reducing voids to raise strength and durability. This article explains the relationship between optimum moisture content and maximum dry density shown by the Proctor test, the design of centrifugal force, amplitude, and frequency produced by a vibratory roller's eccentric weight, and the differing roles of plate compactors and asphalt rollers, alongside current machines from Sakai Heavy Industries and Mikasa Sangyo.
Construction-machinery automation has advanced in stages: machine guidance, which measures blade-edge position with GNSS and IMU; remote operation, piloting by radio from a safe distance in hazardous zones; and autonomous haulage systems now running at mines and quarries. This article organizes MLIT's i-Construction policy, the history of unmanned construction dating back to Mt. Unzen-Fugendake, and the current track record of Komatsu's FrontRunner AHS and Caterpillar Command.