Boom telescope synchronizing and sequencing control

A piece of heavy equipment comprising:

• a base;
• an extendable structure;
• an extension boom system connecting the base structure to the extendable structure, the extension boom system comprising:
• a first actuator mounted on the base, and connecting the base to a second stage;
• a second actuator mounted on the second stage and connecting the second stage to a third stage;
• a third actuator mounted on the third stage and connecting the third stage to an extendable structure;
• a sensor configured to measure an extension of at least one of the first actuator, the second actuator, and the third actuator;
• and
• a controller configured to control the first actuator, the second actuator, and the third actuator to as to selectively operate in a first operation mode and a second operation mode;
• wherein in the first operation mode, the first actuator, the second actuator, and the third actuator are operated substantially simultaneously;
• and
• in the first operation mode the sensor measures an extension difference between one of the first actuator, the second actuator, and the third actuator having the greatest extension and another one of the first actuator, the second actuator and the third actuator having the least extension, and the controller blocks further extension when the extension difference measured exceeds a threshold;
• and
• wherein in the second operation mode, two of the first actuator, the second actuator, and the third actuator are actuated substantially simultaneously, while another of the first actuator, the second actuator, and the third actuator is not actuated;
• and
• in the second operation mode the sensor measures an extension difference between the first actuator and the second actuator, and the controller blocks further extension when the extension difference measured exceeds a threshold.

A method for controlling an extension boom system including a first actuator connecting to a secondary stage, a second actuator mounted on the secondary stage and connecting to a tertiary stage, and a third actuator mounted on the tertiary stage and connecting to an extendable portion, the method comprising:

• selecting one of a first operation mode and a second operation mode;
• when the first operation mode is selected:
• actuating each of the first actuator, the second actuator, and the third actuator substantially simultaneously to extend or retract the extension boom system;
• measuring an extension difference between one of the first actuator, the second actuator, and the third actuator having the greatest extension and another one of the first actuator, the second actuator and the third actuator having the least extension;
• and
• blocking further extension when the extension difference measured exceeds a threshold;
• and
• when the second operation mode is selected:
• actuating only two of the first actuator, the second actuator, and the third actuator simultaneously;
• after the two of the first actuator, the second actuator, and the third actuator are actuated simultaneously, actuating only the other of the first actuator, the second actuator, and the third actuator;
• measuring an extension difference between the first actuator and the second actuator;
• and
• blocking further extension when the extension difference measured exceeds a threshold.