Liugong has introduced a comprehensive "High-Altitude Operation" safety package for its CLG856III and CLG862H wheel loaders. While wheel loaders are primarily earthmoving machines, they are frequently used in ports and steel plants for loading long pipes or logs, where the boom must be raised high. This creates a high risk of tipping over if the machine is on uneven ground or turns while the boom is raised.
The new safety system integrates a 3-axis MEMS gyroscope mounted on the main frame. This sensor monitors the chassis inclination (roll and pitch angles) in real-time. The system is linked to the machine's ECU and the hydraulic control valve block. The logic operates on a "Two-Stage Limit."
Stage 1 (Pre-Warning): If the boom angle exceeds 40 degrees and the chassis inclination exceeds 3 degrees, the system triggers an audible alarm and flashes a "Tilt Risk" warning on the dashboard.
Stage 2 (Active Intervention): If the operator ignores the warning and the inclination reaches 5 degrees (approaching the static tipping angle), the ECU sends a signal to the "Hydraulic Lock Valve." This valve is a solenoid-operated check valve installed in the boom lift circuit. When activated, it blocks the return flow from the boom cylinder, effectively freezing the boom in its current position. It also automatically reduces the flow to the steering system, limiting the steering angle to prevent further destabilization.
The engineering challenge was to minimize the response time. Liugong engineers used a high-speed CAN bus communication protocol, reducing the signal latency to less than 50 milliseconds. This ensures the machine reacts instantly to prevent the center of gravity from shifting outside the stability triangle. This system is particularly valuable for rental fleets where operator skill levels vary, significantly reducing insurance costs and machine downtime.
