Winning business by creating integrated and scalable mechatronic system simulations

Maximizing design efficiency

Cummins is a multinational corporation that has established itself as a leader in the design, manufacture and distribution of engines, power generation products and related components and technologies. It specializes in diesel and natural gas engines as well as generators and alternators for transportation applications, including trucks, buses, construction equipment, agricultural machinery, marine vessels and stationary power generation systems. At the same time, the company has diversified into electric and hybrid powertrains to ensure it can meet the expectations and requirements of all customers.

With such a broad remit, efficiency is key at every stage of the design and development process. Although its products are aimed at optimizing performance and efficiency, Cummins needs the right tools to optimize its own performance and efficiency so it can deliver a competitive price.

“It’s critical for the business to reduce lengthy development cycles and mitigate high costs,” explains Anoop Sunil, machine integration simulation technical specialist at Cummins. “We are often working with customers who are looking to integrate new products or improve existing ones. This would normally mean getting access to their vehicles and running multiple tests, which is extremely time-consuming and expensive. To speed up this process, we employ simulation tools that replace a significant amount of this testing at a much-reduced cost.”

To deliver the most value to customers, Cummins adopted Simcenter™ Amesim™ software, part of the Siemens Xcelerator business platform of software, hardware and services, to create integrated and scalable mechatronic system simulations.

Using Simcenter Amesim to build a hydrostatic CVT transmission model for an OEM that wanted to switch from power shift.

Using simulation to achieve optimization

“By using Simcenter Amesim early in the development cycle, we can optimize designs much further before we build and integrate anything physical,” says Sunil. “It has been particularly useful for our off-highway applications. We use it for energy audits and thermal management studies as well as assessing engine integration, engine downsizing and alternate power solutions. With Simcenter Amesim, we can simulate a range of systems and configurations until we reach the ideal combination of overall performance and energy efficiency.”

Cummins helped one customer that was looking to alter the design of its tractors’ transmission to meet new emissions standards and improve fuel economy. Sunil and his team built a system level model of the entire vehicle using test data from the existing tractor with a Tier 3 engine (an engine that uses technologies to reduce emissions and improve environmental performance). Then they put a Stage V engine (a European off-road emission standard) into the model and replaced the powershift with a continuous variable transmission (CVT) to simulate improvements in fuel economy and transient response. Using virtual energy sensors, they simulated the power consumed by each component and any system power losses. This data was used to inform design decisions for improving overall performance and fuel economy.

“To realize the maximum improvements, we needed to try various engine types and configurations,” says Sunil. “Using Simcenter Amesim reduced the number of prototypes by 50 percent, making this process significantly faster.”

For another customer, Cummins built a model to study the effectiveness of heating an electric bus in cold conditions. The bus thermal management system model included the powertrain and a full cabin, incorporating the material of the seats and glass and a door that opened and closed in line with typical operations. They ran simulations of scheduled bus journeys in various ambient conditions, analyzing the cabin temperature to determine if the heat rejection from the powertrain was sufficient to heat the cabin even in subzero temperatures.

“Without simulation we would have to build a prototype and wait for the right weather conditions for testing,” says Sunil. “By defining the extreme conditions in Simcenter Amesim, we completed all the necessary tests about one month sooner.”

Bus thermal management system model including door and external air circuit.

Winning new business

Sunil says that Simcenter Amesim has been crucial for Cummins in winning business. “It allows us to show what our solution can do for them without having to build or install anything,” says Sunil. “In one instance, we had suggested a smaller wheel loader engine to a customer than a competitor had recommended, which we believed would be able to meet the duty cycle requirements.”

The simulation model included the entire machine with the wheel loader working mechanism and hydraulic system. Cummins compared simulations with both engine types on four different wheel loader duty cycles and proved the smaller engine performed the tasks with better transient response and fuel economy.

“With Simcenter Amesim, we proved that our engine could do the same amount of work as the competitor’s while taking up a smaller footprint and delivering cost and energy efficiencies,” says Sunil. “Without simulation, we would have had to build and integrate physical prototypes that would have taken much longer and been far more expensive.”

Study results show the improvement in the smaller engine for different cycles.

Effectively communicating findings

Simcenter Amesim has delivered benefits across the business, not just directly for the engineers working with it. “The Simcenter user interface is intuitive and makes it easy to display results,” says Sunil. “This allows for much faster troubleshooting and better presentations both internally and for our customers. The inclusion of demos with explanations and informative animations is also a great help in effectively communicating our findings and insights to stakeholders.”

He also believes the software has played a significant part in his own development. “With its vast ready-to-use multiphysics libraries, Simcenter Amesim has been instrumental in expanding my technical expertise and knowledge of off-highway systems,” he explains. “It’s deepened my understanding of vehicle systems and their functionalities, which helps me in my role every day.”

Wheel loader system model for performing an engine downsizing study.

Gaining a competitive edge in future technology

Although Cummins has largely used Simcenter Amesim in the presales process to date, Sunil expects its role to soon be expanded. “The switch to alternate energy sources is happening fast,” he says. “We must be ready for this change, and we can see that simulation will be the fastest and most cost-effective way to keep up and ensure we can efficiently design and integrate future products. By using it early in the development process we will save valuable time and money in the prototype testing phase.

“Simcenter Amesim allows us to conduct comprehensive system level simulation. This means we can assess the performance and interactions of components to provide valuable insights that inform our design decisions. This analysis-led design gives us a competitive edge as technology evolves and we’re able to identify potential issues early and refine designs to optimize efficiency, reliability and performance.”