Types of Mobile Robots – What to use where?

Mobile robots are capable of locomotion, they move around their environment and are not fixed to one physical location. They can be classified in two different ways; by the environment wherein they work and by the device, they use to move.

Let’s discuss different examples of different environments wherein mobile robots can work:

  • Underwater robots or autonomous underwater vehicles (AUVs) which can direct themselves and travel through water. AUVs are also called as Swimming Robots.
  • Aerial Robots are autonomous micro air vehicles, specializing in their guidance and control in the air.
  • Land-based robots categorized as wheeled robots, tracked robots, and legged robots. These are more complex types of robots and are autonomous humanoid as it requires many degrees of freedom and synchronization. Also known as unnamed vehicle group (UGVs), they navigate on inside the house or dry land.
  • Delivery & Transportation robots can move materials and supplies through work with the capability of moving around by navigating through an uncontrolled environment with or without the need for the physical or electro-mechanical guidance system.

Mobile robots can be autonomous or non-autonomous, in order to do the achieve motion, it relies either on guidance devices such as sensors or physical devices that allow them to travel a pre-defined navigation route in relatively controlled space.

Hence the two types of mobile robots are:

  1. Non- Autonomous guided mobile robots
  2. Autonomous mobile robots

Non – Autonomous Mobile Robots:  Guided mobile robots or non-autonomous mobile robots require some sort of guidance system or instruction to make a movement that allows them to travel pre-defined navigation maps in a controlled environment. The pre-defined navigation map such as magnetic tape, bar codes, wire or sensors installed on the environment’s floor that creating an inflexible environment.  These are the following types:

  1. Autonomous Guided Vehicle (AGV): This AGV requires the external guidance system in the form of magnetic strips to travel. These follow a rigid form of the preset route. Typical AGV applications incorporate transportation of raw materials, work-in-progress, and finished goods in support of manufacturing production lines, and storage/retrieval or other movements in support of picking in warehousing and distribution applications. AGVs provide automated material movement for a variety of industries including Automotive, Food & Beverage, Chemical, Hospitals, Manufacturing, Pharmaceutical, Paper.
  2. Rail Guided Vehicle/Cart (RGV/RGC): RGV/RGC is a fast, flexible and easily installed material transport system that travels at a predefined path guided by rails or tracks. RGC has separate input/output stations that allow it to perform multiple operations at once. These mobile robots are an efficient, cost-effective and fast option for complex sorting applications.
  3. Guided Fork-lifts: This specific AGV type is inspired by the conventional human manned forklifts. These forklifts are becoming increasingly complex and intelligent full of autonomy for some applications. These could manned/unmanned traveling with the help of external devices such as tablets, human, etc. The forklift AGV is designed to provide both horizontal and vertical movement of the load.

Autonomous Mobile Robots: Autonomous mobile robots (AMR) are just like humans; can make their own decisions and then perform tasks accordingly. Autonomous robots can perceive their environment and remember it. Based on this info they navigate in a controlled environment without any predefined path or electro-magnetic guidance map, that way they offer flexibility to a large extent. AMRs also optimize the travel distance by calculating the shortest path for every mission & drive efficiency in the warehouse.

Let’s look into a few of its applications:

  1. AMR for Good-to-picking: This includes robots bringing mobile shelf units filled with items to a workstation. In this case, pickers remain at their workstations while software-driven AMRs deliver shelves with different materials directly to the order pickers’ workstation.
  2. Picking Assist Autonomous Mobile Robots: In this case, the robots travel to pick locations, where operators deliver (“pick”) goods based on the robot’s needs. They are an AMR base with an operator interface that provides information about picking order. The robot tells the operator “I want this item and here is where you can find it”. The user interface is also interactive, being possible to provide further info about the product or receiving info from the operator such as “picking accomplished”.
  3. Unmanned Aerial Vehicles (UAVs): These are basically drones moving large products through the air in distribution centers with the help of RFID-scanning technology to offer real-time inventory visibility in the warehouse. Guided autonomously by remote control, UAVs can sense their environment and navigate on their own.
  4. Sorting Robots: These robots play an important role in high speed sorting esp in fulfilment centers. These robots work on a mezzanine with chutes/rabbit holes for location or order positions. Sortation is easily achieved by utilizing a fleet of sorting robots that sort the orders by dumping them through chutes/rabbit holes. The dropped orders or parcels are collected in sacks, gaylords or containers, which will be shipped directly to customers.

Now, along with commercial and industrial sectors, mobile robots are a common sight in public sectors such as hospitals and airports as well. With the evolution of advanced navigation systems & enhanced safety features they are only a step away to become human allies in our everyday activities.

AI and its impact on Human kind

Envision a conversation between the Captain of a mission craft ship and a mission member called Saviour 1. It goes like this – “Wake up Captain, it is 24 hrs to go for landing and as per my protocols I need to wake you up and assist you for landing the Ship”, “How long the crew has been asleep Saviour 1?’ Asked Capt. Ashok. “8 Years, 2 months and 4 days sir” Replied Saviour 1. “We have been asleep too long, kindly brief the exploration mission to the crew again Saviour 1” Said Capt. Ashok, “Crew we will be landing on Proxima Centauri in 24 hrs Earth time. Our goal is to set up the communication back home to inform of our arrival followed by setting up the camp for the crew so that you can carry out the experiments to see the survival on the planet and finally set up the incubation center for the embryos to see their survival on our potential new home. Meanwhile work parallelly on growing food and inhabiting the planet, while the crew will be on the said tasks I will be simultaneously assisting on each tasks, compiling the reports and sending it to Earth for analysis”, briefs Saviour. Who do you think Saviour 1 is? It is an Artificial Intelligence (AI) program designed and developed to assist explorer mission to find new home for humans in the depth of space year 2424.

As depicted in movies across the world it is not necessarily that AI is the ‘self-aware’ program/robot trying to eliminate human race as shown in Terminator series nor it is a slave serving the sentinel beings as shown in Star Wars saga. According to Prof. Professor John McCarthy also known as ‘Father of AI’ “AI is the science and engineering of making intelligent machines, especially intelligent computer programs.” Let us bear in mind that AI is “Artificial Intelligence” as opposed to natural or “Native Intelligence”. AI works on the principle of the computational part of the program that works to adapt itself to be a self-aware system and therefore performs the tasks that the system is designed to perform as if it is using native intelligence. AI has immense potential to contribute to the development of society. As with any technology and tool one could use it for beneficial as well as unsavoury uses. In the scenario envisioned at the beginning of this text where  Capt. Ashok and his crew of astronauts are on a mission in the future to explore an exoplanet and find a new home for mankind, AI could be used to perform manifold tasks in the mission. These tasks could be – a) Finding the best route and optimize the best path to follow in interstellar space, b)  acting as an alarm to the crew, c) performing calculation from the surroundings to find a perfect spot to land, d) setting up the habitat, e) rationing and managing the food supply, programmed to run an incubation center to raise human babies without a womb or a mother, and many others like compiling, screening and processing of data. AI also can transmit data and act as the much needed medical center for the crew so far from home, prepare them for contingencies and finally manage the whole exploration program.

Now let us talk about how AI can be used for our benefit in the real world of material handling here and now.  In our industry of material handling, an intelligent program can work seamlessly across all the stages of intra-warehouse movement of goods, right from inbound operation sequencing to assisting the suppliers to deliver in specific slots, to optimizing the storage location for the goods and, finally order slotting and execution of order picking in the least time with absolute accuracy along with the material movement in the warehouse. Besides doing all the above, AI can also provide real time asset monitoring, data collection from smart devices and provide predictive maintenance insights about devices to the maintenance teams.

With all the discussion and use cases we have still only explored the periphery of the potential and possibilities we can achieve with Artificial Intelligence. In times to come, we will see AI forming a critical element in the practice of safety of the plant, personnel, and systems.

In conclusion, AI has the potential to make Native intelligence also referred to as Human Intelligence to reach a level where it decodes human intelligence itself and reaches superintelligence. On a cautionary note, the goal of development of AI should be to always align with the goal of the human race itself without jeopardising the safety of human race and this planet for it to be a benefactor.

Functional Challenges of Mobile Robots

Over the past few years, mobile robots have started emerging as one of the most important assets in industries for material handling and other intra-logistics operations. These robots have minimized the need for manual handling and an increased number of handling tasks. Little do people realize that even though these robots carry heavy loads but still face functional challenges that are not often noticed and have adverse effects on their maneuverability.

Challenges Synoptic

Mechanical Design Overview

The design of mobile robots capable of intelligent motion and action involves the integration of many different bodies of knowledge. The aim of this system is to idealize an existing autonomous mobile robot, on all levels. This includes the mechanics, kinematics, dynamics, perception, sensor fusion, localization, path planning, and navigation. All these aspects must be reviewed and modified to a modular system if necessary new modular modules must be designed and developed. This way a robust and modular autonomous mobile robot, capable of intelligent motion and performing different tasks will arise.

Mechnical Design Overview

The major challenges include mechanical structure, navigation, and human-centred intelligent control, of which navigation is the most challenging functionality required for such autonomous systems. The navigation comprises four dominant blocks of competencies: perception, localization, cognition and motion control.

  • Perception is the ability of a robot to interpret meaningful data from its sensor,
  • Localization defines how good a robot determines its position in the environment,
  • Likewise, Cognition and Motion control helps in extracting a way to achieve its goal and modulating the motor controller to reach the desired trajectory.

Of all the above four competencies in navigation, localization is considered the most challenging area which requires the greatest research attention.

localization-mobile robot

A Pitfall to Mobile Robots

Assuming one could just attach a GPS sensor to a mobile robot that could solve the localization problem informing the robot of its exact position in the environment. Unfortunately, the current GPS system is not practical with accuracy to say several meters which are almost unacceptable for localizing the mobile robot. Furthermore, the current advancements with positioning technologies are not proving any place in the market especially when it comes to indoors or in obstructed areas. Also, localization is not just limited to determining an absolute pose in space, rather a series of collaborative tasks like building a map, then identify the robot’s relative pose with respect to mapping. In other words, one can say that the robot’s sensors play a crucial role in the localization and the sensor’s inaccuracy and incompleteness contributes to major challenges in localization.

In perception, the major contributor lies with sensor noise and aliasing, further aggravating the problem of localization. On the other hand, using a noise-free sensor alone can’t solve these challenges of insufficient information to identify robot’s pose in the world, instead, it also requires robot programming to recover the robot’s position over time based on series of sensor readings.


Daag ache nahee hain: Vision Management System

Cleanliness is key to holistic healthcare and laundry is an essential but often under-served component in healthcare, addressing this area is “Shubhram Hospital Solutions”, it provides holistic, high-quality linen management and laundering services, guaranteeing infection-free linen that complies with international standards. With their state of the art facility, they ensure that thousands of patients need not face any problems in hospitals.
In order to add more reliability to its process, Shubhram used to manually check the cloth after it was cleaned, this was done to ensure that no stain remained on the cloth and also to add more reliability to the process. In order to make this process more efficient and agile, Addverb provided Shubhram with a “Vision Management System”. VMS captured any stain, wrinkle and identified the torn bedsheets as well. Vision Management System consisted of cameras which were installed at a location that could capture and identify stains. With the help of a sensor and a PLC, VMS could detect any abnormality in bedsheets resulting in rejections and the rejected bedsheets could be further rewashed or discarded.
Quality is a prime business principle and becomes extremely critical in the healthcare sector. Addverb’s VMS added more reliability to the process and enabled Shubhram to operate at 98% accuracy in its daily operations and delighting the customers.

RFID: Enabling Mass Customization

Paytm tied up with NHAI to make the highway tolls cashless, this news went unnoticed until November 8th, when demonetization was announced. Though people were given exemption from tolls for some time, the cashless payment at Tolls got a boost. The underlying technology which facilitates this cashless operation on tolls is Radio Frequency Identification popularly called “RFID”. RFID tags have hit their tipping point and have found wide-spread applications in retail, inventory management, tracking assets and as we discussed above to facilitate cashless payments. The RFID market worldwide is estimated to be at a whopping 10 billion dollars and is expected to reach 20 Billion dollars by 2025.
RFID which traces its root back to World War has been used extensively in the first half of this decade. RFID typically comprises a reader (scanner) and an electronic tag. The reader communicates with the electronic tag by sending a signal. Each tag responds with unique information stored in it. These tags can either be Active or Passive. Active tags are equipped with a battery that allows them to transmit the signal over a long distance approximately 100m while passive tags use the electromagnetic energy of the reader (or scanner) to transmit the signal back resulting in an application for short distances like 20m. The range of the RFID tags varies with the frequency at which they are operating. When frequencies increase the range also increases.
The proof of the pudding is in eating, passive tags have huge potential to disrupt the entire manufacturing process. The ability to store information in RFID tags can change the traditional process of production. Usually, the instructions are passed out manually in a production process and thus necessitate cumbersome process checks and slow down the speed of production also hampering the flexibility. RFID tags can have pre-programmed information about the product and the process. This shall enable the tags to give commands to various elements of production with the help of a reader which shall communicate with the machines, thus eliminating cumbersome process instructions. This shall enable mass customization of products during manufacturing. The use of RFID shall also reduce manufacturing defects and lead to better reliability of the process. Scale and reliability along with flexibility is a dream combination for any manufacturing process and RFID technology seems to provide them.

BEACON : Whose Signal Is It Anyway?

Recently the students of IIT revolutionized the markets of Dharavi by using “beacons” to provide customized offers to the people visiting the markets. This illustration of the ability of beacons to change the entire experience of customers underlies the capability of beacon technology to fundamentally alter various processes across different domains in manufacturing and retail.

What is a Beacon? In ancient times, beacons were fires lit at different locations and used for signaling purposes. They were used to signal warnings, celebrations, navigation, signify an important location, etc. With time and advent of technology, beacons became more sophisticated and their application more widespread and today we typically see a beacon as a very small electronic device type of the size of buttons of a shirt that emits radio signals in close proximity of varying strengths.

How Does Beacon work? Beacons use technology such as Bluetooth, Wi-Fi or UWB. Most commonly used beacons are equipped with Bluetooth Low Energy (BLE) also called Bluetooth Smart. BLE allows the beacons to continuously emit radio signals which contain packets of information. These signals are visible to all the Bluetooth enabled devices such as our smartphones and are sent out typically every 1/10th of a second. In order to emit these signals, beacons have to be connected to a power source such as a battery. BLE requires very little energy as compared to regular Bluetooth and hence the beacons can run even for years with the help of just small button cells.

What shall these Beacons do? The Bluetooth enabled devices (smartphones) through the signal are able to identify the beacon, once the phones identify the signal of the beacon it implies that they are within range of the beacon and a predetermined command on the relevant app shall be triggered. Internet connectivity for this stage is necessary for the app to trigger the command. These commands can be discount coupons, navigation options, any new product arrival, register attendance, etc.

The signals that beacons emit can be used to measure the location of the device around the beacon. The signal strength can be converted into the distance to know the exact location of the device from the beacon. Though one inherent problem that can occur is that beacons emit radio signals and they can be absorbed by objects in between the receiving device thereby altering the strength of the signal and thus affecting the conversion into the distance. With another technology, it is completely possible to address the problem but let us reserve it for another day!