The Mecanum Wheel Is So Weird, It Is Genius. How It Works

The mechanical wheel is a device of very strange appearance yet it is one of the most curiously satisfying things to watch in motion The first time I saw one of these although it may sound unbelievable was on a forklift It was very surprising to see how this thing moved sideways like a crab and smoothly towards dad I felt like I was watching Michael Jackson do the moonwalk It's simply the unnatural oddity of feeling bad yet being so satisfying to watch which is exactly the experience I had I wanted to know how it moves like that To truly understand how the mechanical wheel works we have to look at it from below Yes that's why I have this camera installed down here What we're going to do is show you a view from below I have a remote-controlled car that I built We have some mechanical wheels We'll go step by step and see if we can figure out how we can get all these strange movements from this interesting tire design Let's start Very well ladies and gentlemen let's start with a single wheel Turn on the lights Ah isn't it beautiful Focus on this wheel here Let's turn it forward This is the front part of the vehicle Let's see what happens when we tell this wheel to move forward Well he doesn't want to move forward Actually he wants to move a bit inside the vehicle Well before moving on to two wheels I want to point out that the wheel's orientation is very important here First if we look at this vehicle from above you can see that it points downward and toward the center of the car in this way But if you look at it from below even though it seems strange to look at it from above I know it actually points in this direction like this Correct There Very good Then let's try the left version of the wheel Now you should aim more towards the inside of the car While from above as you can see it's like this Alright Here we go We are going to turn this wheel forward This is the front of the vehicle What happens then Okay So far we have learned that the wheel definitely wants to follow the roller's axis because the wheel is free to rotate along this axis It slides a bit on that axis but has full traction in this direction And so without any other wheel to add more power it will want to continue along that line of traction Hello Let me put the correct wheel here because I actually want an X pattern and we are going to test it with two wheels So looking from above you can see that the rollers point inward toward the vehicle like an X and from below Very well What happens when we have two wheels moving forward What happens with two wheels going backward Here is where things get interesting When there is only one wheel on the vehicle it will tend to move along the axis of the roller that is in contact with the ground But when you combine the two they go in a straight line Why Well if we look at the direction of the forces each wheel of the car wants to exert we can see that part of the force is canceling out The way we do it in physics is to take a force vector the line along which the force acts and break it down into X and Y coordinates to make it a bit easier to see where the energy is going In this case you can see that each wheel has a force pointing inward and a force pointing forward Okay the two inward forces are equal and cancel each other out It's like adding 5 and then subtracting 5 You get zero force in this direction but you still have all your force forward and therefore you end up moving forward But the smart part is that you can decide which forces to cancel by choosing the direction you turn the wheels Let me show you If we put the two wheels on the same side like this Now we can move sideways like a crab Let me show you Isn't that great Look at that Inward movement When they rotate at the same speed it works well Outward movement And since we have four wheels we can double that force and make them all work together Now there are other movements that can also be created It can be made to rotate on its own axis It can be made to pivot left and right There are all sorts of interesting things that can happen just by turning the wheels in different directions Isn't that amazing Now as with anything in engineering there are pros and cons Therefore what I am trying to say here is that we are not going to throw away all traditional wheels And start putting these much more expensive and costly wheel designs on our vehicles just so they can move sideways But when those features are important to you you add them And that's the part that makes engineering so fascinating I have the opportunity to explore all these different options I love how we come up with all these smart ideas to meet these unique applications Achieve the best possible performance at all times Now just look at this wheel to know that it will require more maintenance It will be more expensive and more complicated to manufacture So when you would use something like this as we mentioned before it has some advantages and disadvantages Maneuverability is the main priority The first thing that comes to mind is the application I showed it to you before which is the forklift Powered industrial trucks must be able to maneuver in very tight spaces They move very slowly which is another limitation You wouldn't want to use them in a high-speed application But in a warehouse where employees walk and move very heavy loads you will want to move slowly anyway Therefore once again speed is a good application Maneuverability is extremely important so you can fit the maximum amount of inventory into the smallest space possible You need a forklift that can lift something very heavy and also reach tight spaces That's when it makes sense to get something like this Another application where we see many mechanical wheels is robotics in controlled environments And when I say controlled environments in this case I mean smooth and uniform floors Like the floor of a hospital or a factory a warehouse where concrete is paved everywhere Since the mechanical wheel has a design limitation in traction allowing it to have maximum human maneuverability You also need ideal soil conditions But a hospital is a great example of that isn't it Do you want to be able to move medications or supplies around a hospital with a mobile robot A mechanical wheel is a great example of how to fit into that application In this type of environment you would want sensors that alert you when you're about to hit an obstacle Whether it's a moving patient hospital staff stretchers or carts in the hallway That's why maneuverability is extremely important Do you want to be able to detect those obstacles and maneuver in any possible way to get around them That is why a mechanical wheel is a fantastic example of how to meet that need And once again we will make some concessions But these concessions are worth it to obtain this kind of benefit Therefore in summary you should consider the mechanical applications where maneuverability is of utmost importance The wheel may be a bit more expensive because you need to enter tight spaces You have ideal ground conditions You won't have to climb stairs or anything like that This is a robot that can easily enter an elevator maneuver smoothly on a flat and predictable floor Now I wouldn't consider this wheel very accurate because due to its design it can slip But that doesn't mean you can't use it in precision applications For example you could have a robotic arm on a wheeled base so it can maneuver into position It won't be the perfect position but it will be very close Then your robotic arm can have a camera or some other means to detect its distance from the object Reach out grab it no matter what the task is In this way your precision does not have to depend on the wheels themselves Everything depends on how you design the robot And that's why I'm so intrigued by this because I'm currently trying to design a robot that can be used as a teaching tool to get people excited about robotics Now we're not talking about a robot like this as if it were too difficult It required all my knowledge and skills And all that knowledge and skills were pushed to the limit in many disciplines That's not something you want people to try to do when you want them to learn something new So my goal is to design a pair of different robots In fact I want to create a very easy version and a slightly more difficult one to get many people excited about robotics And I want to guide you through those steps but this is a challenge for me I'm still figuring it out No I haven't resolved all the details but I do know that the great factor for me with the mechanical wheel is quite high which is an advantage I haven't mentioned so far But don't underestimate the brilliant factor when you're trying to excite people about something Don't forget that Michael Jackson made a lot of money with his moonwalk And I think I can get a lot more people interested in robotics if I use something like a robot So why not design my teaching robot with a mechanical wheel base It's not because I'm going through a specific app It's because I want people to get excited about robotics I'm going to make a simpler version of this robot so it's accessible to people with minimal tools and experience but we can start Then I plan to make a harder version for those who might already know a bit about machining or welding or are trying to explore those areas These pieces will be a bit more challenging but trying to build two robots at the same time will take a lot of effort And that's why I need PCB to help me manufacture some of the parts In fact last year I had the exact same problem I was working on a huge project called Doctor Who There's a full video about it if you want to watch it I'm sure you haven't seen it because I can see the view count and I know you haven't watched that video But I can tell you that it was one of the most challenging large-scale constructions I've ever done Y PCB A printed these large resin prints I couldn't get anyone else to do it except them They helped me a lot I enjoy working with them Of course they also make PCBs They do sheet metal work They do CNC machining In fact I had to replace Jarvis's front plate in an incident that we won't go into here But anyway all I did was send them to make a 3D model they machined it and they sent me the part Everything went well and I went back to work Now later in the series you will hear more about PCBWay because they are going to manufacture parts for me But I wanted to tell you before the invoices start that if you want them to make custom parts take a look at PCBWay I'll put a link in the description Hello the last issue is that we need to make some decisions about what we are going to do with this robotics project I need to calculate a budget I'm trying to figure out how much they are comfortable paying For example if you had to spend $150 on supplies would more people be involved than if you had to spend $250 I mean I know that on a mobile scale the lower the number the more people will be able to do it But there's a threshold where we lose capability isn't there You know the more money we're willing to spend the more capable the robot will be The less we spend the more people we can involve But what is the difference between $150 and $200 Would that really change the number of people who would take the creation of a robot seriously I don't know Help me figure it out I have no idea I'm not even convinced we need to use the mechanical wheel for the base But you have to admit that the cool factor is pretty high isn't it In the end it's really smart and interesting to watch and I hope to use it to attract more people to robotics That is my true goal I need you to help me solve the rest Thank you for watching the video