In our previous post we discussed methods in generating concepts while designing a satellite. One of the beauties in design is that there are so many tools with different processes and ways of thinking which can allow the creative types and those who are more structured and like a systematic approach for inspiration. We will cover tools that are mentioned in Ulrich & Eppinger’s Product design book [1]. These tools and processes are as follows:
- Looking at current solutions
- Literature reviews
- Talking to experts.
- Patent searches
- Function decomposition
- Classification tree
- Concept combination table
Looking at current solutions
Looking online for solutions to a similar problem or looking at competitive products is a good way for inspiration for potential ideas. If we were designing an Earth Observation (EO) CubeSat we could look at current and past EO satellites and look at potentially useful features that could replicate or improve on. We can also look at solutions for similar problems that aren’t related to space. For the Claymore deployer there were solutions in retail, automotive and aerospace.
Literature reviews
Conducting literature reviews are a great source for finding out the latest research carried out within your field. We could find potential concepts to our EO mission that we could have never thought of based on what we find. For example, we could find new ways for imaging processing, mechanisms for our lenses, new image sensors, thermal control systems, ADCS mechanisms, file compression, data link etc. In addition, by reviewing the research findings, research methods and conclusions we can identify potential ideas that will be a technological dead end. If we want to be ahead of the curve in terms of performance or innovation there are plenty of research that are state of the art in our field, and it is a resource that can be overlooked. Another benefit (that will help our next step in concept generation) is that we can acquire contacts who are researching in relevant technologies we want to adopt.
To carry out a literature review effectively you should identify what subjects you want to find out so in our case it could image processing for EO missions. We would then identify how recent the publication we want to review. Generally, you want to limit it to within five years unless some breakthrough happened earlier. To get the most of your literature review you then list out the keywords in your search to ensure you can find the most relevant papers in your research. So, in our example we would have “Earth Observation”, “image processing” “CubeSat imaging” “CubeSat earth observation” “Data processing for imaging”, “Data downlink methods” and “CubeSat data downlink”. This isn’t an exhaustive search, but you should start with a couple of keywords. If you can’t find enough relevant papers you should look at alternative wordings which is why “data processing” and “data downlink methods” are included as they could yield results that may be relevant for our solution.
When reviewing your initial results, you should read the abstract and conclusions first and consider whether the paper is relevant or not as you may need to sift through 100s of journals to find what you are looking for. Bookmark the potential candidates in your research then continue the search. Then you can review the papers in detail.
Talking to experts
Talking to individuals who are experts, researchers, lecturers or people who are highly knowledgeable in areas relevant in our EO mission. They can provide you information and give you advice not just for concept generation but throughout the development of our satellite. By developing this relationship, we could possibly acquire collaborative projects and missions that benefit both parties. For example, we contacted a research team who are developing a new advanced imaging sensor who gave us a lot of ideas for our satellite. Since they are at the final stages of development, we identified that we could incorporate their sensor into our satellite. The research team get to have their hardware in space and tested in a real application while we have acquired a new advanced imaging sensor that could provide us better quality images than the leaders in the market. Plus, if this mission goes well and the researchers get to spin out a new company we could also have supply of these sensors in the future. Creating win/win scenarios should always be priority in life.
Patent searches
Patent searches are a wealth of knowledge for new ideas and can give you inspiration for generating concepts for your project. Obviously, you can’t copy what has been patented but inspecting how the invention has been designed you can find possible alternative methods to your project.
Function decomposition
Figure 1High level function decomposition of EO Cubsat mission
Before any concepts can be developed and chosen it is best to initially identify the functions of our satellite. We will breakdown our EO CubeSat into inputs and outputs (Figure 1) so that we can investigate further and develop solutions for each subsection. In our example the satellite input is receiving commands. Output is sending images back down to Earth.
Figure 2 Detailed function decomposition of EO Cubesat mission
We can then breakdown the function analysis further in a more detailed function decomposition (Figure 2). This graph can help determine how our satellite will convert the inputs into our required outputs. In our example we want to identify all the functions that we need to send our images back down to Earth. We will break our inputs into smaller sub functions and identify how they produce an image back down to the ground station. Image below gives you a simplified example of our EO. Some projects and products will require multiple functional breakdowns. Key tip is to focus on the actions required from each function. You don’t need to link every function up as sometimes they can’t logically be linked but focus on listing all sub functions and actions required. We can also list out our customer needs in a separate function decomposition diagram which may highlight other functions that may not have been identified with a user action orientation. Breaking down complex systems like satellites makes coming up with concepts to solve the issues less daunting.
Figure 3 Function solution table
Once we identify the actions for each sub function, we can list them into a table (Figure 3) and identify possible solutions to our problems. In our EO mission our two examples are positioning the satellite and locating satellite. In the table we can see the various methods in how we could achieve these functions. It’s best to come up with as many ideas as possible during the concept stage so you and the team can go from the obvious and sensible to the most ridiculous and unfeasible concepts. This approach enables you to expand your horizons and possibly find multiple candidates which can be down selected in the future.
Classification tree
Figure 4 Classification tree of solutions to positioning the Cubesat
We can then place our ideas into different classifications with the classification tree (Figure 4). We can then eliminate or “prune” ideas that wouldn’t meet our EO mission needs. We can also use this tool to revert to our function decomposition and add more steps, inputs or requirements. When it comes to engineering design you will at times revert to previous stages as you learn and identify new issues that were never foreseen. This diagram can also help the team put more time and effort into investigating the other functions of your satellite.
Concept Combination Table
Figure 5 Combination table
As we developed our functions and selected the potential solutions that have the most promise we can then put them along with our functions into a combination table (Figure 5). The combination table is used to develop concepts for each sub function based on the various combinations we have identified. This tool can help teams develop a large volume of concepts. How this tool works is you first pick an input then draw a line to one of the possible solutions to each function. Once you have created a path from input to output you then sketch a concept. You can sketch multiple ideas from the same combination.
In this post we have covered a more systematic methodologies to generate concepts for our satellite. If we combine the methods and tools that were covered in a previous post, we can have a more creative blue sky thinking or something a bit more organised. In doing so we can develop a diverse range of concepts and designs.
A concept generation toolbox based on the tools mentioned in this post has been created. This is freely available in the link below and in the DLC page:
Bibliography
[1] K. U. &. S. Eppinger, Product Design and Development, New York: McGraw-Hill Education; 6th edition, 201