Extensive sensor technology for compact workhorses

Extensive sensor technology for compact workhorses

Increasing urbanization and the associated lack of space are significantly changing the requirements for construction machinery. In narrow streets or courtyards, machines are required that are maneuverable, easy to transport and multifunctional at the same time. Manufacturers are responding to this by no longer thinking of compact machines as pure “mini” versions of large devices, but rather as independent product families with modular attachment concepts and assistance systems.
For example, Volvo CE has a model in its portfolio, the “ECR25 Electric”, which is a battery-powered mini excavator that shows how compact electric machines can be used in emissions-sensitive areas. There is a wide range of approaches to electrification. Komatsu, for example, has systematically electrified its mini class and presented several models such as the “PC 20E”, “PC 26E” and the “PC 33E-6” available from Kuhn Baumaschinen, which work with batteries and are designed for emission-free operation.
Accordingly, it is hardly surprising that the market for compact machines is continuously growing. According to forecasts by market researchers, a volume of over 50 billion euros should be reached by 2030. However, behind this growth there are also major challenges, such as a shortage of skilled workers, stricter environmental regulations and digitalization requirements, which force manufacturers and users to make sometimes costly adjustments.

Increasingly networked construction sites

The battery used in each case largely determines the possibilities of electric compact machines. Manufacturers currently mostly rely on lithium-ion technology, but this only has a limited service life and there are high replacement costs in the event of a defect. Alternative models such as lithium iron phosphate (LFP) offer a longer service life, but at the same time have a lower energy density, which reduces operating time.
Fast charging systems theoretically allow charging to 80 percent during lunch breaks, but typically require expensive infrastructure that is missing on most construction sites. Inductive charging systems promise contact-free charging, but are maintenance-prone and inefficient. Modern compact machines are equipped with extensive sensors, which increases manufacturing costs. Acceleration sensors monitor vibrations and shocks, temperature sensors detect critical operating conditions, and pressure sensors control hydraulic systems. The collected data requires powerful data processing and storage capacities.
With the “L 507 E”, Liebherr has a battery-electric compact wheel loader in its range that combines the familiar kinematics and work processes with an electric drive train. Such models show that the transformation among manufacturers is not limited to individual niches, but is finding its way into central product lines. At the same time, development is being driven forward. Wacker Neuson, for example, has electric variants in its portfolio and has electric mini excavators in its range that are specifically advertised for inner-city operations. Yanmar is expanding its in-house compact offering with, among other things, track loaders and a range of electrified devices for the European market. Caterpillar has also expanded its own portfolio and, among other things, equipped it with assistance functions.

Capture operational data in real time

The fact that electrification is technically possible does not automatically mean that it is already part of everyday life. In practice, users face several problems. Battery capacity is just one limiting factor among many. The larger the battery, the longer the battery life, but the greater the weight and potentially greater transport challenges. Manufacturers are trying to defuse this conflict of objectives through modular battery systems, efficient drive and hydraulic concepts, and fast charging options. But the infrastructure on construction sites often lags behind; There are not enough charging points everywhere, and not every construction site allows connection to strong grid connections. In addition, the acquisition costs for electric variants are usually significantly higher than for comparable diesel models, which makes the economic viability calculation more difficult for smaller companies. Funding programs, leasing and rental offers play a major role here in overcoming the higher investment hurdles.
Parallel to the drive change, the importance of digital systems is growing. Telematics is no longer just an issue for large machine parks: compact machines are also increasingly being networked in order to read out operating times, operating states, charging status and maintenance requirements in real time. The ability to capture real-time operational data opens up new opportunities for fleet management, predictive maintenance and cost control. This allows construction companies to better assess which machines are at capacity, when service work will be required or where there is potential for savings. The data obtained helps fleet managers to optimize utilization, plan service appointments in advance and calculate total costs over life cycles more accurately. There are also assistance systems that increase precision or improve safety on tight construction sites.
Condition monitoring systems are intended to predict wear and optimize maintenance intervals, but require continuous calibration and updates. Predictive maintenance can reduce unplanned downtime, but the algorithms required are complex and maintenance-intensive. Machine learning systems for anomaly detection require extensive training data and regular adjustments. The operation of compact machines is constantly evolving; voice control is intended to make operation easier in difficult working conditions, but is susceptible to disruption in construction site noise. Gesture control theoretically reduces physical strain, but requires precise calibration and is prone to errors.
Haptic feedback simulates surface texture even on remote-controlled machines, but requires complex technology with a limited service life. Virtual reality training enables risk-free training, but the high acquisition costs are only amortized with intensive use. Augmented reality systems for information overlay are maintenance-intensive and have limited use in poor lighting conditions. Compact machines are also gradually being integrated into networked construction site systems, but one problem with this is data protection and security risks.
Cybersecurity is becoming more and more of a challenge because networked compact machines represent potential attack targets. Accordingly, manufacturers need to expand their focus on developing security architectures without compromising usability. This makes the certification procedures more complex and expensive, which in turn often puts smaller manufacturers at a disadvantage. In addition, communication between machines to avoid collisions only works reliably if there are uniform standards, which, however, have not yet been established. Digital twins – images of the physical machines – are intended to enable simulations and optimizations, but require continuous data updating and, above all, computing capacity.

Cost factor

From the user's perspective, three questions are central: Is the battery capacity sufficient for the planned working day? Is the dealer network strong enough to ensure fast service? And can the investment be presented economically? Manufacturers such as Volvo CE and Komatsu provide specific data on capacities and charging options for certain models, but the usable runtime remains highly dependent on temperature, load profile and operating patterns. This is precisely why detailed preliminary planning is recommended for construction companies: short-term rentals for testing in real operations, leasing models with service packages or integration into sharing platforms can reduce the risk and provide experience before capital is tied up in the long term.
Another aspect that is often underestimated is the training of staff. Electric and digitally controlled compact machines differ from classic diesel vehicles in terms of operation and maintenance. The training offering is correspondingly broad. Anyone who uses this not only benefits from greater efficiency, but also from less downtime due to incorrect operation or improper maintenance. The standardization of interfaces for attachments and battery packs is another lever that could accelerate the acceptance of electrified compact machines. Uniform couplings, quickly replaceable battery modules and interoperable telematics standards would reduce logistical effort and facilitate the reusability of accessories across brands. So far, individual manufacturers have chosen proprietary solutions, which limits flexibility. The market will have to respond to regulation or industry-wide cooperation in the next few years if sharing models and interoperability are to work on a larger scale.