Optimising robotic performance: best practices for industrial engineers

In the future, machines or robots will significantly increase the efficiency of industrial processes.

Introduction

Robots have evolved from performing repetitive, simple tasks to handling complex operations across various industries, such as manufacturing, logistics, healthcare, and more. They have higher precision, reliability, and cost-effectiveness. Industrial engineers must ensure that these robotic systems always operate at peak performance. Optimising robotic performance requires a deep understanding of the technology, meticulous planning, and continuous improvement. In this article, we will explore best practices for industrial engineers to enhance the efficiency and effectiveness of robotic systems in industrial settings.

Definition of robotic performance

Robotic performance, in the context of industrial engineering, refers to the ability of a robot to perform its designated tasks efficiently and effectively with precision and reliability. It encompasses a range of critical parameters, including speed, accuracy, repeatability, and adaptability. A well-optimised robot should exhibit consistent and exceptional performance across various operational scenarios, increasing productivity and reducing errors. Achieving optimal robotic performance is enhancing a robot's speed or accuracy and fine-tuning it to operate seamlessly within its intended environment.

Industrial and service robots are two categories classified according to their application.

Industrial robots are machines used in industrial automation that can autonomously control, move, and rotate along numerous axes. These robots, such as hand-guided and serial manipulators, can be mobile or fixed.
Collaborative robots (Cobots) have enhanced industrial robots. These robots work along with humans and interact with them using end effectors. A device that interacts with the environment is known as an end effector.

Factors affecting robotic performance

Robot type: Different types of robots demand different amounts of energy. For example, an enormous, heavy-duty robot could need more energy than a minuscule, lightweight robot.
Task performance: A robot's energy usage is determined by its task. Tasks requiring a lot of movement or heavy lifting may require more energy than static tasks.
Operating conditions: A robot's energy consumption might be influenced by operating conditions such as temperature, humidity, dust, or other contaminants.

Best practices for optimisation of industrial robotic performance

The first step in optimising energy usage is to measure the robot's energy consumption while in operation. Installing energy monitoring sensors and meters on the robot or its power supply allows the process to be carried out. The experimental setup for detecting temperatures (joints 1-3, gearbox and ambient joint 2) and obtaining motor current data from the industrial robotics (IR) controller is given below.

Figure 1: Configuration for detecting temperatures and collecting motor current data from the industrial robot controller

After measuring energy consumption, data must be analysed to detect patterns and trends in energy usage. This research can be used to find opportunities to optimise energy usage throughout robot operating times.

Proper robot selection: It is critical to select the right industrial robot for the specific operation in the manufacturing process energy consumption during working hours. Larger and heavier robots frequently use more energy than smaller and lighter robots. Using energy-efficient components, motors, batteries, and sensors can reduce energy consumption during robot operation. Here are some essential variables to consider:

Payload capacity: Select a robot with a payload capacity that matches the application's needs. A robot with a higher payload capacity will use more energy, whereas one with a smaller payload may need to work harder to complete the task.
Minimise robot weight: Weight significantly affects energy consumption. Minimising the robot's weight and payload reduces its energy needs.
Robot arm reach area: Select a robot with sufficient arms to do tasks without unwanted movements. A robot with an excessively extended reach will use more energy.
Robot arm speed: Choose a suitable robot arm speed for the application. A robot that moves quickly consumes more energy than needed, whereas a slow robot may take longer to complete.
Energy efficiency features: A robot with energy efficiency characteristics is recommended. Regenerative braking, energy recovery, and low-friction bearings reduce robot energy use.
Maintenance: Well-maintained robots use less energy. Maintenance and calibration of the robot's joints and bearings reduce friction and energy losses. To reduce robot maintenance time and cost, choose an easy-to-maintain robot. Look for a robot with an easy-to-use interface for diagnostic and repair.
Application-specific features: Robots with application-specific features may include vision systems, force sensing, and sophisticated sensors. These features can reduce energy usage by improving the robot's precision and efficiency.
Flexibility: Choose a robot that can be reprogrammed and repurposed for various jobs, reducing the need for additional robots and saving energy.
Decrease inertia of moving arms: Inertia is the resistance to motion changes. Robot arms and joints require less energy when their inertia is reduced. This can be done by adopting lightweight materials or optimising robot component design.

Energy-efficient motors in industrial robots: Electric motors control the axes of industrial robots, which execute activities such as grabbing, moving, and manipulating things. The robot's size, weight, and power requirements determine the amount of energy consumed by these motors. Using energy-efficient motors is critical in optimising energy usage in industrial robots. Industrial robots frequently require large amounts of energy, and motors are one of the most energy-intensive components. Energy-efficient motors are built to be highly efficient, converting more of the electrical energy they receive into mechanical energy. Energy-efficient motors can cut energy usage by up to 50% in industrial robot operating times compared to traditional motors. The following actions can be taken to include energy-efficient motors in industrial robots:

Determine the motor types currently used in the robot and the energy consumption associated with each motor.
Investigate and find energy-efficient motors to replace the robot's current ones.
Calculate the possible energy savings by comparing the energy consumption of present motors to energy-efficient motors.
Evaluate the performance of the energy-efficient motors to ensure they fulfil the robot's operating criteria and standards.
Replace the current motors with more energy-efficient motors and undertake performance testing to confirm that the robot works adequately.

Robot programming optimisation: The way a robot's motions are programmed can have an impact on its energy consumption while in operation. Industrial robot route and motion optimisation to minimise superfluous movement can reduce energy consumption in working schedules. Avoid needless motions, quick acceleration, and deceleration, as these might waste much energy. Motion planning that is smooth and efficient might help to reduce total energy use. Optimising robot path algorithms to provide energy-efficient paths can significantly reduce energy consumption. Techniques such as trajectory optimisation, path smoothing, and factoring energy costs during path design can be used to reduce energy consumption. Simulation tools can be utilised to model and analyse the energy consumption of various robot behaviours, algorithms, and system configurations. This can assist in identifying energy-intensive locations and directing optimisation efforts. Machine learning and artificial intelligence techniques can teach robots energy-efficient behaviours and adapt their actions to the environment and task requirements. As a result, efficient working programming and intelligent working schedules for industrial robots can help to reduce energy consumption by minimising superfluous movements and optimising the robot's path.

Figure 2a: Minimising energy for robot arm movement

Figure 2b: An energy-efficient cloud-based mode of operation for robotic applications

Energy monitoring during the working period of robots: Energy monitoring can help optimise industrial robots' energy usage. To optimise energy consumption, it is vital first to establish how much energy the robot uses at different stages of operation. By monitoring robot energy consumption, it is possible to establish energy consumption patterns and determine which processes and components consume the most energy from robots so that they may be analysed and optimised. This can be accomplished by putting energy meters at various spots throughout the robot's system to monitor the amount of energy spent. This information can then be analysed to determine places where energy consumption can be reduced.

Figure 3: The closed-loop control of MPC (Model predictive control) in terms of energy consumption monitoring of industrial robots

Regular maintenance of industrial robots

Regular maintenance ensures that industrial robot components perform effectively during working hours, reducing energy usage. This includes inspecting and maintaining worn parts and lubricating the robot. Industrial robot energy efficiency and consumption depend on regular maintenance. Tips for maintaining energy-efficient robots:

Implement predictive maintenance: Check and maintain the robot's gears, bearings, and belts. Poorly maintained robot mechanical parts use more energy. Industrial machinery and devices need regular maintenance to avoid malfunctions and maximise energy use. Predictive maintenance methods like robot performance monitoring and issue detection can help keep the robot running efficiently.
Clean air filters: Dirty filters can impair robot cooling system efficiency and increase energy usage. Robots cool better when air filters are cleaned or replaced regularly.
Keep robot motors and sensors clean and debris-free. Electrical components that are dirty or damaged might increase robot energy use.
Reduce friction to save energy by lubricating robot parts. Lubricating robot joints reduces friction and improves movement efficiency. This reduces energy use and extends robot life.
To maximise robot efficiency, monitor and optimise its programming and control system. Reduce computations, idle time, and superfluous movements with algorithms and logic [135].
Train operators and maintenance staff on energy efficiency. Energy optimisation and best practices should be promoted throughout the robot's lifecycle.
Replace worn or damaged parts immediately to save energy.
Clean the robot's workspace to reduce energy use and maintain smooth operation.
Regular energy audits can discover energy efficiency improvements.

Conclusion

Industrial engineers play an essential role in enhancing robot performance by performing duties such as selecting equipment, programming, and calibrating robots, seamlessly integrating sensors and visual systems, and prioritising safety and data-driven analysis. By practising these standards, engineers ensure that robotic systems perform to their full potential, resulting in efficiency, quality, and competitiveness in today's industrial operations.