Boom Lift Crawler Chassis with Hydraulic Actuation (Test Harness)

This example models the hydraulic actuation system for the chassis of a boom lift. Four actuators extend and contract to position the outriggers, and two other actuators control the separation of the two tracks. This model is used to examine the hydraulic system.

This model is a test harness from the main model (see documentation).

Contents

Model

Open Model

Component Under Test

The component under test is a hydraulic actuation system for the chassis of a boom lift. This includes the outriggers and track extension actuators.

Double-acting cylinders with three pilot check valves extend to lower the outrigger. The pilot check valves lock the cylinder in place when the 4-way valve returns to center, even if a hose upstream bursts so the outriggers don’t collapse. Two pilot check valves are on the extend side of the cylinder in case one fails while the system is in use.

The track actuation system inculudes a four-way valve that determines if the track separation increases or decreases. There are no valves to lock the cylinders mid-stroke.

Simulation Results: Chassis Sequence

The plots below shows the result of a test sequence that extends and retracts all actuators in the chassis (outriggers and tracks). The test sequence includes signals for all valves so that the test sequence can also be run on the full model.

Below is the corresponding prescribed motion for the test. This allows testing on a full model that has motion for any combination of the actuators.

Motion of the outrigger actuators along with applied actuator force.

Hydraulic pressures in the outrigger actuators along with actuator position.

Motion of the track actuators along with applied actuator force.

Hydraulic pressures in the track actuators along with actuator position.