Boom Lift Crawler Tracks with Hydraulic Actuation (Test Harness)
This example models a hydraulic system that sets the separation of the tracks on a boom lift. Two hydraulic cylinders extend or retract to set the separation. A directional valve controls if they extend or retract. No additional valves are needed to lock the tracks in place as they are not intended to be used in a situation where gravity can influence their position.
This model is a test harness from the main model (see documentation).
Component Under Test
The component under test testing is a hydraulic system sets the separation of the tracks on a boom lift. The hydraulic network contains a four-way valve that determines if the track separation increases or decreases. There are no valves to lock the cylinders mid-stroke. Because fluid can move between the cylinders even if the 4-way directional valve is closed, the tracks will shift to one side if pushed on the other (unless the cylinders are both fully extended or both fully retracted).
Simulation Results: Lift Sequence
The plots below shows the result of a test sequence designed to only extend or retract the 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 track cylinders along with applied actuator force.
Hydraulic pressures in the actuators along with actuator position.