Stewart Platforms are designed to replicate movement across six degrees of freedom with accuracy down to micrometres. They're used in various industries, from drones in the sky to satellites in space, bringing precision to different fields. These platforms can simulate complex movements, opening up many opportunities. Similarly, they are also designed for precise positioning applications, where motion or speeds aren’t crucial. Applications like alignment of a secondary mirror on large telescope.
Hexapods today are utilised in several industries, mainly in Aviation, Defense, Space, Automotive Testing, Energy, Optics, Imaging, Machine Tools, Medical Surgery and Research, Naval Simulation, UAVs and Drones, Research & Engineering, Experimental physics and more, mainly for simulation, training or entertainment purposes. There are hexapods right now in Space as well!
Take James Webb Space Telescope (JWST) for example. Launched in 2022, JWST was built with the help of hexapods across various stages of production. The primary mirrors of the space telescope were assembled and aligned using hexapods with sub-micrometre precision and were also calibrated by another hexapod. The French Mid-Infrared Instrument (MIRI) imager was aligned using a hexapod and likewise for the secondary mirror which uses a hexapod for alignment. In fact, there are two Hexapod on Mars as well, aboard the Perseverance Rover.
What makes Stewart Platforms a reliable solution is their precision, consistency and programmability. With the right set-up, these platforms can run for long hours without losing accuracy. And they are fast! Fast enough to isolate vibrations or stabilise a platform to compensate for waves in the ocean. Programmability is the game changer, which makes it adaptable to a wide variety of application. Imagine coding flight pattern (motion profile) from a drone into the hexapod to replicate the same flight pattern on ground. It’d help to improve design and development process considerably, while saving time and expensive field testing.
Motion simulation unlocks a world of benefits. Motion simulation not only saves time and resources but also offers insights that traditional methods can't match. Programmability allows complete control over the movement of the hexapod, where you can program complex trajectories, nuanced sequences, and worst-case scenarios, all with a straightforward interface. For example, testing of vehicle's sub-systems such as suspension systems during prototype stage or simulating harsh conditions experienced by satellites during launch, in a controlled environment would save boat-load of money!
Hexapods have proven to be quite cost effective by providing real-world like movement. Be it satellites, a spacecraft docking system or an unmanned aerial vehicle, it’s important that systems and designs are thoroughly tested and perfected before heavily investing on them. Thus, understanding every aspect of their motion, especially in extreme or unfavourable conditions becomes necessary. Satellites cannot be tested in the “field” before they are deployed and in other cases like vehicle testing or boat simulations, field tests are expensive and resource intensive, leaving various aspects of studying motion to chance.
In the entertainment industry, Stewart Platforms have been used in motion simulators and VR experiences. A common example is a racing simulator. The six degrees of freedom allows you to experience zero gravity as well. As you are robbed of your visual sense wearing a VR headset, the platform through its intricate movement can subtly trick you into a weightless experience! With great hardware and software integration, Stewart Platforms can prove to be the perfect tool providing high-fidelity, immersive experiences.
Virtual Reality is a domain as buzzing as space! Watch this space (pun intended) for more content merging the two domains.