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Tennant T7AMR Robotic Floor Scrubber 2018

Tennant T7AMR Robotic Floor Scrubber 2018
Tennant T7AMR Robotic Floor Scrubber 2018

Designers: Tou Yia Thao and Peter Tabeling, Tennant Industrial Design, Minneapolis, Minnesota, USA
Manufacturer: Tennant Company, Minneapolis, Minnesota, USA

Tennant T7AMR Robotic Floor Scrubber 2018

Project Description

What is it?

The Tennant T7AMR is a robotic floor maintenance machine which can be operated manually or autonomously. Featuring a “teach and repeat” user interface, operators can easily program the machine to clean automatically. This autonomous mode allows customers to do more cleaning with less labor, and enables employees the ability to focus on high-value tasks that otherwise may go undone.

The design embraces the Tennant Visual Brand Language and integrates the many sensors and cameras that work together to inform the artificial intelligence required to safely guide the machine on its intended route.

To embrace sustainability, the machine is equipped with on-board technology that converts ordinary tap water into an ionized, non-polluting cleaning solution. This system uses 70% less water than competitive machines, and eliminates the purchase, handling, and disposal of expensive or toxic cleaning chemicals.

Challenge Faced:

Training - Mobile autonomous robots are complex, technology laden devices. However, the cleaning operator is often a low-skill laborer with little training and experience. To be successful, the team had to make the use of the technology simple to understand and deploy. No one wants to buy an expensive robot only to find out it takes an engineer to make it work. It must perform as intended right out of the box.

Safety – The thought of a 1000lb machine operating in public spaces without an operator can be a scary thought. Therefore, the team had to develop software and hardware solutions which would confidently detect and react to the unexpected - and always do no harm.

Labor – Businesses generally view the cost of cleaning as an overhead expense. Therefore, doing more with less is essential to the profitability of cleaning contractors and the efficiency of internal employee cleaners. It is difficult to attract and retain workers, and employees often give little, if any, notice when they are leaving.

Modularity – The T7AMR is a variant of a conventional floor maintenance machine. The design needed to consider how to integrate the autonomous technology and do so in a way which would enable it to be built with as many common parts with the conventional machine as possible. This is important to achieve manufacturing efficiency, cost and part proliferation control, and simplicity of field service.


Productivity – For a robotic machine to provide a positive ROI for its owner, it must perform the daily tasks that a human would normally complete. By making the machine easy to deploy autonomously, the regular operator can start their shift by getting the machine working on the floors while they attend to other cleaning tasks. Additionally, the machine creates an on-board, activated water cleaning solution. This reduces the time spent working with detergents and increases runtime by consuming 70% less water than competitive machines.

Safety – The machine leverages a series of sensors and cameras to constantly monitor its environment for unforeseen obstacles. This could be a box or a display rack that has moved into the cleaning path, or a curious child that has come close to watch the robot work. In addition to this artificial intelligence, safety precautions like barrier belts and weight sensitive switches ensure that no one gets hurt and possible shenanigans by passersby end without drama. To prevent surprise, turn indicators signal the machine’s intended course.

Modularity – To reduce risk, the design strategy sought to combine significant new autonomous technology with a proven floor cleaning platform. As a result, the design team had to create new body structures to integrate the autonomous technology onto a conventional machine. The final design successfully integrated multiple, strategically placed, sensors, 3D cameras, and lidar units into the front shroud. By modifying only the parts that needed to change to make the machine autonomous, manufacturing and service has been optimized.

User Experience:

Working with a robot can be intimidating for operators. Also, competitive machines that are not easy to program often wind up being an “expensive experiment” as they sit idle in a storage closet.

To make the T7AMR easy to deploy as an autonomous floor cleaner, the team worked to minimize the technical knowledge required for success, so that ordinary equipment operators could get the machine to perform. This was achieved by utilizing a simple premise of “teach and repeat” methodology. Specifically, to switch the machine from manual to autonomous modes, the operator must first drive the machine to a QR code label that is placed within their facility. This QR code is scanned by the machine and is then defined as the starting point. Next, the operator manually cleans their space while their actions are recorded. They complete the programming by returning to the starting point. This closes the loop and makes a map that can be repeated autonomously. With the map created, the user gets off of the machine, closes the operator station safety barrier belts, and presses “go”. The machine will begin cleaning without assistance. With the machine working on its own, the operator is free to attend to more important, less monotonous work that only humans can do.

Beyond robotics, effort was made to make it easy to fill, empty, and clean the tanks. The tank hoses are prominently labeled “clean” or “dirty” and the tanks open through large hatches to make cleanout simple.

Benefit to Client:

Customers purchase an autonomous floor cleaner to reduce the amount of labor required to clean a space. Also, a robot never complains, calls in sick, or doesn’t show up. Additionally, robotic cleaning is very consistent. The path the robot takes is recorded and can be displayed to the cleaning managers as confirmation that their spaces were cleaned. This is a very important benefit known as “Proof of Performance”. With conventional tools and cleaning methodologies, there is a general lack of trust between the managers responsible for the cleaning and their cleaners. The managers worry about losing their contracts if cleaning quality suffers and frequently don’t know if their employees are going to show up and do the job. The data provided by the T7AMR solves this question and provides proof to their customers that cleaning has occurred. Therefore, manager anxiety is reduced and contracts are retained.

Benefit to Society:

Autonomous cleaning machines free people from having to do laborious and repetitive tasks and focus on those jobs that require greater thinking and involvement. This higher value assignment elevates the cleaner to the increased challenge of these value-added tasks and provides them with a “co-bot” in which they can manage.

Cleaning has traditionally involved the use of chemicals which find their way into the environment. Studies show that operators very often misuse the chemical additives; adding much more of these pollutants to the machine than is required to achieve the proper clean. This is known in the industry as measuring by the “glug, glug” method. EC-H20, or electrically activated water, provides outstanding cleaning in the majority of situations. This activated water introduces no toxicity into the environment and very quickly reverts back to normal water. The net result is a machine which is very kind to the environment and doesn’t require it’s users to purchase, handle, or measure chemicals.