Software Makes Solid Impact

Programs are helping hydraulic systems do more while reducing operator workloads.

March 1, 2014

Terry Costlow

Software is increasing as designers deploy more controllers like these silver boxes from Bosch.

Digital controls continue to expand their reach, impacting everything from the intricacies of engine operations to the interactions between operator and machine. This takeover has driven an explosion in the amount of software running on all types of electronic control units (ECUs).

Electrohydraulic systems have seen significant growth as most vehicles’ overall volume of software soared. Programs control valves and other equipment, interact with operators, and ensure that safety regulations are met.

Managing software has become one of the major challenges facing electronic development teams. Once developers decide which functions can be managed by software, they have to determine how to create and verify code that improves the efficiency of electrohydraulic systems.

Growth spurt

New demands for features and a greater focus on safety are among the factors forcing suppliers like Mico to keep adding more software.

During the past five years, there has been a rapid expansion of software’s role in the operation of equipment. For example, most hydraulic functions are now controlled by software that manages minute internal actions as well as the link between operators and equipment.

Plenty of coding is needed to meet growing HMI requirements. (Eaton)

“In the past, the software focus was mostly upon core work and drive functions essential for the success of the machine in the market while auxiliary functions remained hardwired,” said David Eckerd, Product Management Director at Bosch Rexroth. “Now, many toolboxes contain equipment to diagnose machines electronically. Integrating more functions into the electronics controls increases the diagnostic coverage of the machine while improving overall reliability by utilizing solid-state switches instead of contacts and/ or diodes.”

Regulations also play a role in the expansion of software. An increased demand for safety is a key factor, and the drive to meet tighter emissions and fuel consumption laws is also fueling the growth of software.

“With the change of regulations like the European Union’s requirement for ABS on faster moving vehicles, and new types of transmissions such as hybrids with regen braking, there is a steady increase on software in hydraulic controls,” said Manfred Maiers, EH Group Director at Mico Inc.

The human touch

Programmers are turning to new tools from suppliers like MathWorks.

As programs control more electrohydraulic functions, software is the de facto link between equipment and operators. Digital displays, touch panels, and electronic buttons and joysticks all run code that lets operators do more tasks with less effort. Some observers feel growth in human-machine interface (HMI) software is just beginning.

“The automation of certain functions requires more HMI application software as well as control software,” said Eddie Phillips, Marketing Manager, Electronic Controls and Software, at Eaton’s Hydraulics Business. “In the next five years, I expect to see an increase in human interface controls that’s greater than the growth we have experienced in microcontroller applications in the past couple of years.”

When this increased usage of HMIs instead of gauges and push buttons is combined with globalism, designers can leverage software’s ability to transcend national borders. It is easier to translate text displayed on a screen than to alter printing on a physical gauge. There are also a number of visual cues and images that can easily be understood without words.

“Since messages can be displayed in the local language, or status can be displayed via warning symbols, graphical indicators, or gauges, this increases the operator’s understanding of the system by allowing him to quickly understand the message,” said Kirk Lola, Business Development Manager at Parker Hannifin Electronic Controls Division. “A display that shows operating condition, as well as error and status messages, greatly reduces operator confusion.”

Controllers from Parker help keep programs running in real time.

The expanded role of software is driving a change in the way code is developed. Many design teams employ automatic code generators, which create programs in a more systematic style than human programmers. This method is faster and it makes debugging more straightforward.

“After design verification is carried out at the model level, engineers use automatic code generation to implement the software,” said Wensi Jin, Automotive Industry Manager at MathWorks. “Code generation allows for faster implementation and eliminates coding error. With model-based design (MBD), people commonly get time and cost savings of 40% or more compared to traditional development methods.”

Software teams are also benefiting from the trend to visual programming languages. These development tools help engineers focus on system challenges rather than figuring out how to create code.

“A major change in the development of application software is the advent of graphical programming tools,” Lola said. “The advanced programming tools are becoming more popular as they reduce development time and expense, as well as allow system engineers to focus on the system design rather than the minutiae of embedded software development.”

Doing it all

Many new functions are coming as programmers figure out ways to automate tasks. Some of this automation improves vehicle efficiency. For example, software can change fan speeds or turn them off to reduce power demands. Other programs make life easier for operators.

Parker is putting more emphasis on CAN connectivity to help systems communicate.

“In many cases, the machine software can semi-automate a task so that the coordination and training required of the operator is significantly less,” Lola said. “A good example of this is a side loader refuse truck. By allowing the arm lift and retraction to be automatically coordinated, operator training can be reduced and productivity can be increased. In addition, when the control system coordinates the two functions, the operator can concentrate on other aspects of operating the truck.”

Hardware and software are also being used to improve safety. Putting safety-related functions under software control requires developers to ensure that code will run without any glitches. That means verification, validation, and testing play a critical role in safety.

“Many features and functions have arisen in the areas of functional safety,” said Bosch Rexroth’s Eckerd. “High reliability design principles such as redundancy and diversity are used in interconnecting controllers into machines, which requires the development of new software functions. To support demanding functional safety requirements, software must be coded and verified in a very specific manner to assure a predictable response in detecting and reacting to trigger conditions.”

Regulations are another factor that shine the spotlight on software reliability. Product design teams must show that they have gone through several iterations to reduce the potential for errors before many products can be sold internationally.

“Legislation has also driven additional safety requirements, which increased the need for — and complexity of — software,” Eaton’s Phillips said.