Application Spotlight: Telehandlers – Longitudinal Load Moment Limiter (EU Regulations) with Customized Extensometer
The challenge
Telehandlers (short for telescopic handler) are versatile, mobile machines for lifting, moving and placing heavy loads. To prevent instability during the loading process, the EU established the EN15000:2008 standard, which covers the static and dynamic longitudinal loading of telehandlers. The regulation requires that the machine shut down if the strain on the telehandler’s back axle exceeds the specified threshold.
To help telehandler makers comply with EN15000:2008, VPG Force Sensors developed a Longitudinal Load Moment Limiter system that is compliant with the standard. It has been successfully adopted by several customers.
The solution: VPG Force Sensors extensometer-based system
The heart of the VPG Force Sensors EN15000:2008-compliant Longitudinal Load Moment Limiter system is the Model 182 Extensometer. This customized extensometer comes with dual-channel strain gauges, providing full redundancy for continuous, uninterrupted measurement. The Model 182 Extensometer is exceptionally flexible, as it is available with several output-level trim options. For this application we recommend the J1939 CAN bus connection, the standard communication bus for the automotive industry designed by the Society of Automotive Engineers. The Model 182 is also extremely accurate, enabling it to be used in low-strain situations.
Implemented in the Longitudinal Load Moment Limiter system, the Model 182 can provide constant readings, making failures more apparent in the unlikely event of a system fault. The 182 Extensometer is bolted to the rear axle of the telehandler, where it can monitor for overweight or unbalanced loads that might cause the machine to tip over.
The Load Moment Indicator (LMI) is the brain of the system. It manages the audible and visual warnings issued to the telehandler’s driver, as well as the automatic shutdown. The LMI includes the CAN bus for communicating with the machine’s electronic control unit (ECU). Each LMI can be customized to meet the specific design requirements for each machine. The LMI is mounted in the telehandler’s cabin, keeping it within the operator’s view.
The simple interface of the LMI provides early warning of overloading or an unbalanced load.
Benefits
This innovative solution enables telehandler makers to build-in advanced safety features and meet regulatory requirements for ensuring their equipment operates only within the intended load limits.
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Learn more about force sensor solutions for telehandlers and other construction applications
