Taking the stress out of machine operation

Taking the stress out of machine operation

Volvo Construction Equipment is taking a different approach to operability and investing early on in the product development process. By thinking of operators as part of the system, the company’s engineers are concentrating on smart machines, operator support and autonomous functions.

There’s a lot to think about when operating construction equipment – from hitting productivity targets, to safety and working in the most fuel efficient way. And with the limited capacity of the human mind, it’s often people themselves that set the limitations of a machine – not the equipment itself. Volvo Construction Equipment (Volvo CE) knows that operators are under high stress levels when using machines. That’s why, by monitoring operator’s vital functions and simulating the interaction between the operator and their working environment, Volvo CE engineers are looking to develop smart machines that are aware of the operator’s workload and can adapt accordingly. By allowing the machine to take over as much as is possible (and appropriate) the operator can focus on the job at hand – resulting in increased productivity, fuel efficiency and safety.

Intuitive machines 
Dr. Reno Filla, a research engineer in Volvo CE’s emerging technologies team, recently carried out a study simulating the operability of wheel loaders. “Traditionally machines are sold on productivity and fuel efficiency,” says Dr. Filla. “But the main concern for operators is to hit productivity targets – they’ll only think about fuel and energy efficiency if they have time. Therefore, to improve efficiency it is essential to consider operability early on in the concept development phase. If a machine works intuitively and reduces the operator’s workload he or she will have the capacity to process additional information and think about more than just productivity – such as how they’re driving the machine.”


Dr. Filla used computer simulation to mimic the interaction between operators and wheel loaders and then assess machine operability – something which has not been done before. “By carrying out this testing at the concept development phase (as opposed to the usual process of building a prototype for operator testing and then collecting feedback) the cost of exploring new ideas is lower, the project is quicker and it’s easier to make changes to the machine,” explains Dr. Filla. “We created an operator model by interviewing wheel loader operators and finding out exactly how they use the machine. When put together with other computer programs which simulate the machine, this introduced a human element and created a dynamic simulation model which describes how an operator uses the equipment. Simulation can never replace all physical testing but it will lead to better final solutions and significant savings in product development time and cost.”

Measuring stress
Volvo CE is also measuring how the mental workload (stress) of the operator affects body signals like heart rate (pulse), heart variability (the change of heart rate), skin conductance level (perspiration on the hand), finger temperature and respiratory rate (breathing). “From these physical tests we conducted on wheel loader operators at work we can see that they experience high stress levels,” says Dr. Filla. “After analyzing the data we can’t say that one working situation is ‘harder’ per se than another because there are a lot of outside factors that affect stress levels. But we can say that there is more contributing to stress levels than just the physical task of operating the machine. There is a high mental workload – operators have to plan their work, constantly think about safety and be adaptable – it’s far more complicated than just performing a particular working cycle. From these tests we can see that we need to build a machine that helps the operator as much as possible.”

Taking the stress out of machine operation

The machines of the future 
Volvo CE is working on future machine designs that will make the operator’s working environment less stressful. The machines of the future will adapt to the operator’s needs. For example, if the machine could determine that an operator was stressed and in need of help it would assist him or her by taking over certain functions. “Future machines will be less dependent on operator skills,” says Dr. Filla. “Systems will support operators with guidance and even take over the control of primary functions which will allow the operator to act in a more supervisory fashion.” Volvo CE is working to automate certain functions in its machines from active safety, to driving sequences and autonomous bucket filling and emptying. Some of these projects are more advanced than others. A few could be decades away, others could be in production within two years.

Taking the stress out of machine operation   

Picture 1: Volvo CE is working on making the operator environment even less stressful.
Picture 2: Heart rate, skin conductance and finger temperature were measured to determine stress while the machine was operated.
Picture 3: Dr Reno Filla, research engineer at Volvo CE’s emerging technologies team.