Introduction
Human-Machine Interfaces (HMIs) have become an essential part of modern manufacturing systems, which allow operators to monitor and control automated equipment. The design of HMIs is not only a usability issue in custom automation facilities, but it also directly influences productivity, safety, and trainee training time. Poor interfaces are confusing, lead to operator errors, and extend the training. A well-thought-out HMI design can easily be learned to allow operators to respond quickly to issues in production.
Why HMI Design Directly Impacts Training Time
Industrial operators often make quick decisions because they organize and oversee multiple production processes simultaneously. In applications like Robot Pick and Place systems or Robotic welding cells, the HMI is the control station primarily for the monitoring of machine status, alarms, and the production flow.
Poorly constructed or crowded interfaces are detrimental to learning because operators spend more time trying to determine how the layout is organized rather than how a task is performed. Moreover, training time is also longer when HMIs are not consistently laid out or contain too many visual elements. Rather than their simple navigation, operators may need to learn multiple screen patterns.
Alarm Design Rules That Prevent Operator Confusion
Alarm systems are the most problematic part of industrial HMIs. Improperly designed alarms may result in the operator failing to distinguish between major malfunctions and minor alerts.
Alarm designs have the following important rules.
Prioritize Critical Alarms
When something goes wrong, operators must know about it. Critical alarms should be highlighted so that they stand out among the usual updates.
Avoid Alarm Flooding
Too many alarms at the same time may disorient operators. Alarm flooding leads to alarm fatigue, where operators begin to ignore alarms as they come too frequently.
Use Clear Alarm Messages
A code of technical errors seldom helps operators with what they should do. Instead of generic messages like:
- Error 1052
- The system should have clear instructions, such as:
Conveyor Motor Overload
Operators can reply quickly without technical interpretation in plain language.
Group Related Alarms
Alarms should be organized by machine function or system. One such example would be to install the conveyor alarms in one place and the welding cell alerts in a separate location. This setup makes troubleshooting easy and time-saving.
Screen Layout Best Practices for Industrial HMIs
It is essential to have a readable screen layout for usability. Each screen will be intentional and contain information in a readily understandable form.
One Purpose Per Screen
Every display needs to focus on one machine area or process. The multi-purposes in a single screen can lead to crammed layouts.
Use Consistent Navigation
Operators should also know where they are in the system at all times. Users can navigate through screens using regular menus and navigation buttons.
Follow Visual Hierarchy
Relevant information, such as machine status, alarm, and safety indicators, must be brought to the fore. Smaller or less central places may provide secondary data.
Avoid Overloaded Screens
There is too much data that prompts cognitive load. The operators should only view the information that they are handling at the moment.
A typical HMI system used in industry comprises:
- Overview dashboard
- System area screens
- Maintenance screens
- Alarm screen
- Diagnostics and troubleshooting tools.
- This tiered approach allows operators to see detailed demand information.
Designing Operator Flows That Match Real Workflows
An effective HMI reflects how operators interact with machines on the production floor.
Operating map Operator mapping may be used to initiate the design process- the functions used by operators in a standard production process, maintenance process, and troubleshooting.
Once these workflows are known, the HMI should be developed in such a way that it aids them.
Reduce Clicks
Indicators of critical controls and machine status should be available. Long route directions slow reaction speed and frustrate.
Provide Context
Operators can and should be able to view machine status, alarms, and key controls on the same screen whenever possible. This will reduce the switching between screens during troubleshooting.
Designing Under Stress.
When machines fail or production is disrupted, operators must accelerate. The HMI should present vital information in a manner that allows decisions to be made automatically without necessarily having menus to consult.
Common HMI Design Mistakes That Increase Training Time
The proliferation of HMI systems may be difficult to utilize because they evolve with time, lacking any direct design strategy.
Common mistakes include:
- Too complicated navigation systems.
- Excessive color, flash, or animation.
- Uneven placement of buttons between screens.
- Technical instead of direct descriptions.
- Difficult to find alarms or alerts.
- Benefits of a Well-Designed HMI System
- A proper HMI will be productive and efficient.
Key benefits include:
- Less training and quicker onboarding of operators.
- Reduce the training costs of new employees.
- Less operator error in manufacturing.
- Quickly diagnose failures as they occur.
- Improved equipment performance and availability of machines.
- Better safety compliance with more apparent alerts and controls.
Conclusion
The HMI design should be viewed as a critical component of the system engineering by the manufacturers investing in modern automation systems. A well-thought-out interface allows operators to familiarize themselves with machines within a brief time, respond to issues effectively, and stabilize production.
