Selecting a mobile robot for heavy loads

Mobile robots are becoming an integral part of the factory of the future. Autonomous mobile robots, also known as AMRs, are increasingly versatile and can support various material handling tasks. In addition, within a production environment they can help to reduce the workload of employees, take over routine tasks and comply with hygiene regulations, an issue that has grown in significance due to the current coronavirus pandemic. Experts predict the mobile robots market in this context will grow from 18.7 billion USD in 2018 to 54.1 billion USD by 2023.

Decision makers in factories often assume that these advanced machines are particularly suitable for short, clearly defined distances and relatively small transport volumes. However, the following explanations and tips show how AMRs also make an ideal solution for transporting larger loads over longer distances and what companies should consider when purchasing mobile robots for their own operations.

AMRs play a major role in transforming supply chains by optimising the traceability, speed and accuracy of routine operations. In warehousing and manufacturing they make processes more efficient by working safely side-by-side with humans and reducing the risk of employee injury in dangerous situations. To meet the needs of flexible production, manufacturing sites must be agile enough to change or update a production line at short notice. Since mobile robots aren’t fixed, they support this call for flexibility. Furthermore, innovative robots such as OMRON’s HD-1500 can transport loads weighing up to 1500kg. This provides those handling, for example, pallet-size loads and large and heavy automotive components to expand their application options.

Autonomous mobile robots vs forklifts and AGVs

Forklifts are among the main sources of accidents and serious injuries in warehouses, and understandably many manufacturers are now looking to mobile robots to reduce these risks thanks to their capability to carry heavy loads. However, when considering integrating mobile robot solutions to replace forklifts in a manufacturing facility or warehouse, it is important to rethink the entire process and understand the manufacturing flows. For instance, mobile robots are ideal in warehouses with automated storage and retrieval systems (ASRS) as long as the loads can be picked up by the mobile robot. When looking at WIP (work in progress) applications, mobile robots can bring great benefits in automotive manufacturing, adding flexibility to applications where the components are already transported on conveyors or shuttles.

Autonomous guided vehicles, also known as AGVs, are often used in applications where material needs to be moved between facilities, covering distances greater than 300 metres. However, mobile robots can also bring value in long distance applications if multiple input and output locations are needed, especially if it’s important to make changes during transportation such as calling the mobile robot to carry out an urgent task. In short, AMRs are a good solution for last-metres delivery where flexibility is required.  

When selecting a mobile robot for moving heavy loads, there are five key areas to consider:

1. What are the payload requirements?

When selecting the right mobile robot model for their operations, decision makers must first consider the loads that need moving. Mobile robots with lower payload capacity are normally less expensive and more agile than models for heavier loads. The HD-1500 can move pallet-size payloads in manufacturing facilities, making it a viable alternative to forklifts. Since it is built with sturdy metal skins, the machine is robust and able to withstand heavy unintended external impacts. Onboard sensors are protected as the robot completes demanding tasks.

2. How easy is the solution to deploy?

Mobile robots are easy to implement and can move freely without predefined routes, providing flexibility to the user. They are easily reprogrammed according to the task and are capable of calculating their own trajectory in real time, working safely side-by-side with people. They enable easy collaboration between humans and mobile robots, but also between various types of mobile robots and other machines. A good fleet management system will help to maximise investment by coordinating the AMRs so that they share the tasks, minimising the number of robots required.

Modern mobile robots can automatically calculate the best route for material transportation while navigating safely around people and obstacles without the use of magnetic floor tapes or other guides. A typical example is a robot designed to deliver packages to a fixed location while automatically avoiding people or obstacles in its path. The robot can identify its own position by comparing the results from a laser scanner with an onboard map.

3. What is the impact on safety?

According to a recent study, 54% of respondents from 33 countries stated that one of the most frequent accident risks in European companies is the lifting and moving of heavy people or loads. Innovative mobile robots can take over these tasks while also improving safety thanks to extensive features that avoid collisions and obstacles. When an obstacle is detected, the robot can react dynamically by slowing down instead of abruptly stopping.

The most advanced models are also capable of moving at high speed in aisles as narrow as three metres. Other useful features are 360° safety coverage and stop position accuracy, supporting a collaborative and safe working space. As such, mobile robots are rapidly enhancing the safe automation of material transport operations in industries worldwide, not only to meet labour shortage challenges but also to manage the risks associated with the spread of the coronavirus.

4. Battery price vs performance?

Onsite logistics – the movement of products and material within the factory and warehouse – is becoming a bottleneck for many companies due to the frequency and tediousness of the job, compounded by rising labour costs and the need to meet social distancing protocols. Fast-paced manufacturing environments require speed and flexibility. When selecting the right mobile robot for a specific application, another important aspect to consider in this respect is the battery price versus performance. Companies must decide if they would rather invest in a low performance battery that will need to be replaced within a couple of years or a more powerful battery with up to 11 hours uptime and 9000 charge cycles, ensuring 10 years of operation 24 hours a day with a charge time of just 36 minutes.

5. How flexible is the solution and what kind of add-ons are available?

Manufacturers such as OMRON are increasingly focusing on the ability of robots and machines to interact seamlessly. This enables production runs to be quickly and easily altered to allow for fluctuating lot sizes while reducing the need for workers to carry out repetitive tasks and heavy lifting. Autonomous robots can be programmed with artificial intelligence (AI) to recognise and learn from their surroundings and make decisions independently. A practical example for the use of mobile robots in food and beverage manufacturing is waste bin handling in the area of recycling. Supported by system integrators and with specialist add-ons, mobile robots can handle tasks such as picking up and emptying waste bins.

Greater collaboration

Over the years, the face of manufacturing has changed considerably – and it continues to do so. Now, a new phase is starting as machines are working more interactively with people. Companies such as OMRON are looking towards the future of manufacturing by developing solutions that involve greater collaboration between man and machine. With the option to be equipped with a collaborative robot arm, mobile robots are well-suited for working side-by-side with human colleagues in many applications by taking on tasks such as moving loads from conveyor to conveyor, thus increasing flexibility and efficiency in the production environment.

A new generation of mobile robots will help to ensure the future of manufacturing by enabling production sites to be much more agile, completing diverse production demands such as lifting and transporting heavy loads while offering flexibility so that companies can adjust rapidly to meet changing consumer needs. In turn, this will enable manufacturers to be more responsive, more productive and ultimately to enjoy greater profitability.

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