When a piling rig operates in directional or cluster wells, it is essential to follow the design requirements of the construction project. Understanding the drilling direction and trajectory at the piling rig's head is crucial for accurately controlling the advancement of the drill bit, ensuring that the piling rig drills along the designed trajectory.

Although it's impossible to see or feel the direction of the drill bit underground, blind drilling should be avoided. Therefore, mastering underground wired or wireless measurement technologies is vital. These technologies can continuously track the coordinate position of the piling rig's drill bit underground. If any deviation is detected, ground-controlled downhole tools can be used to correct the drill bit's direction promptly.

Currently, the most advanced underground wireless measurement instruments are MWD (Measurement While Drilling) and LWD (Logging While Drilling). These instruments can automatically transmit measured data from underground to the surface. After processing and simulation by a computer, adjustments can be made to the structural parameters of the downhole controllable tools at the surface, thus achieving control over the piling rig's trajectory.

The use of downhole controllable tools can reduce the number of times a piling rig needs to be lowered, significantly improving work efficiency and reducing the labor intensity of the piling staff. This method is also known as semi-closed loop drilling underground.