Excavator four-bar linkage length and angle offset determination using a laser distance meter

Abstract

An excavator calibration framework comprises an excavator, a laser distance meter (LDM), and a laser reflector. The excavator comprises a chassis, linkage assembly (LA), sensor, implement, and control architecture. The LA comprises a boom, stick, and four-bar linkage (4BL) with the sensor on a 4BL dogbone linkage. The control architecture comprises a controller programmed to execute an iterative process at successive implement curl positions. The iterative process comprises generating a measured dogbone angle θ, determining a height Ĥ and a distance {circumflex over (D)} between an implement node and the LDM, and determining an implement node position. The iterative process further comprises determining an estimated implement angle θand generating a mapping equation comprising linkage angle inputs (θ, θ) and n unsolved 4BL linkage length and angle offset parameters. The controller is programmed to generate and solve a set of m mapping equations comprising the n unsolved parameters.