Finding the Perfect Match: Different Heavy-Duty Mobile Applications Call for Different Actuators

Abstract

For the longest time, valve-controlled, centralized hydraulic systems have been the state-of-the-art technology to actuate heavy-duty mobile machine (HDMM) implements. Due to the typically low energy efficiency of those systems, several promising, more-efficient actuator concepts have been proposed by academia as well as industry over the last decades as potential replacements for valve control—namely electro-mechanic actuators (EMAs), displacement control and different types of electro-hydraulic actuators (EHAs). This paper takes a closer look on the application side to figure out where which of these novel solutions can be a better alternative to conventional concepts, and where they fail to improve. Application characteristics such as number and sizes of actuators, typical frequency and amount of power demands, or recuperation potential are classified as low or high for different machines fulfilling typical work tasks. To classify, duty-cycle video analyses and/or simulations in Simcenter Amesim were done for wheel loaders, excavators, backhoes and telehandlers. As counterparts, actuators are rated in their compatibility with the application characteristics. The ratings of both, applications and actuators, are numerically expressed and used to calculate mismatch values for different application-actuator pairings. The calculation method is modular and can be easily applied to additional applications or actuator concepts. Finally, the lowest mismatch value indicates the actuator concept which is the "perfect match" for a certain application. Low mismatch values could be found for wheel loaders in combination with zonal EHAs, excavators and telehandlers with displacement control or centralised EHAs, and backhoes with conventional load-sensing actuators.