Boom Lift Crawler with Abstract Actuator Models and Controller

This example models a boom lift using abstract models of the actuators. The lift has 6 hydraulic actuators in the chassis, 7 hydraulic actuators in the boom plus one other passive hydraulic cylinder. The lift was modeled in CAD, imported into Simscape Multibody. The actuators are modeled using prescribed motion with transfer functions to represent the delay in the hydraulic system.

The model includes a simple control system which restricts some of the movements when the lift is in certain positions. Simulink dashboard blocks permit manual testing of the algorithm

Contents

Model

Open Model

Overview of Actuation Systems

The boom lift crawler consists of a chassis and a boom.

The chassis has:

The boom has a number of actuators to position a basket with the operator:

Mechanical System

The mechanical model was created in CAD software and imported into Simscape Multibody. It includes many closed-loop linkages and models ground contact for the outriggers and the tracks.

Abstract Actuators System

The actuator models are abstract. The joints in the model move using prescribed motion, and a transfer function models the delay from the hydraulic system. This subsystem converts the on/off signal for the actuators to a position.

Control System

A very basic control system checks signals from sensors on the boom lift and determines if the user inputs should be permitted or overridden.

Simulation Results: Full Sequence

The plots below shows the result of a test sequence designed to activate all actuators on the boom lift.

Motion of the outriggers along with applied actuator force.

Motion of the tracks along with applied actuator force.

Motion of the lift, extend, and jib actuators along with applied actuator force.

Motion of the tilt, and basket leveling actuators along with applied actuator force.

Motion of the turret and basket rotation actuators along with applied actuator torques.