In-situ profilometry for transient testing of automotive materials

启停技术现已广泛应用于批量生产的汽车上。发动机能够在不需要电力的时候自动停止(例如，在红绿灯下)，并在司机需要再次移动时迅速重新启动。这是一项节省燃料、减少尾气排放的有用技术。然而，随着车辆变得越来越老，这项技术也存在潜在的问题。发动机需要运转才能产生保护表面免受磨损的油膜。当发动机停止并再次启动时，摩擦和磨损量与其持续运行时相比增加。这可能是一个问题，因为车辆变老了，因为它们可能比预期更早磨损，导致环境排放，更换成本高昂。目前还没有测试标准来比较汽车材料表面在反复停止和启动时的表现，因为在这一领域所做的科学工作很少。在这个项目中，我们将建立一个传感器，它将测量表面在多次停止和启动时的损坏程度，并将其与连续运行时的表现进行比较。这是具有挑战性的，因为表面通常覆盖着石油，很难测量，这意味着人们通常必须等到测试结束才能测量它们。然后，他们必须进行许多测试，试图找出整体行为。事实证明，这既昂贵又不切实际，因此连续测试通常是更可取的。我们建议开发一种传感器，它可以自动测量在一次测试中产生的磨损量，这将使比较发动机中不同材料在瞬时(启停)条件下的行为变得更容易。为此，我们将建立一个基于霍尔效应传感器的轮廓仪。这种传感器使用磁铁来检测身高的变化。我们将使用3D打印来构建一个柔性件，它将非常锋利的钻石尖端和霍尔效应探头集成到一个组件中，然后将其连接到一个3轴电机控制器上。这将使我们能够在表面停止时快速扫描表面，并测量启动和停止操作的速度有多快。测量油污表面具有挑战性，因此我们将开发使用压缩空气清洁表面的新技术。如果成功，这将使我们能够测量现有材料的耐久性，这些材料受到环境友好型启停操作的影响。然后，测试可以用来寻找新的材料和涂层，以确保它们将持续车辆的生命周期，而不会过早退化，导致更多排放或发动机维修成本。最终，该项目可能是为我们的车辆选择未来材料的关键，因为该方法模拟了真实的发动机驾驶条件，并将构成汽车材料测试标准的一部分。

Start-stop technology is now widely available on mass-produced automotive vehicles. The engine is able to automatically stop when power is not required (at traffic lights, for example) and quickly start up again when the driver needs to move again. This is a useful technology that saves fuel and reduces exhaust emissions. However there are potential problems with the technology as vehicles get older. The engine needs to be running to generate the oil films that protect surfaces from wearing out. When the engine is stopped and then started again, the amount of friction and wear increases compared to when it is continuously running. This could be a problem as vehicles get older as they may wear out earlier than anticipated, causing environmental emissions and being expensive to replace. There is currently no test standard to compare how the surfaces of automotive materials behave when they are repeatedly stopped and started as little scientific work has been done in this area.In this project we will build a sensor that will measure the extent to which surfaces are being damaged when they are stopped and started many times and compare it to how they behave when they run continuously. This is challenging as the surfaces are often covered in oil and difficult to measure, meaning people usually have to wait until the end of the test to measure them. They then have to perform many tests to try and find out the overall behaviour. This proves expensive and impractical, such that a continuous test is usually preferable. We propose to develop a sensor that automatically measures how much wear was being generated in a single test, which will make it easier to compare how different materials in the engine behave under transient (start-stop) conditions. To do this, we will build a profilometer based on a Hall effect sensor. This sensor uses a magnet to detect changes in height. We will use 3D printing to construct a flexure that integrates a very sharp diamond tip and the Hall effect probe into one assembly and then attach it to a 3-axis motor controller. This will allow us to scan surfaces quickly when they have stopped and measure how fast start-stop operation is wearing them out. It is challenging to measure oily surfaces, so we would develop new technology that will clean the surface using compressed air. If successful, this will allow us to measure the durability of existing materials that are subject to environmentally friendly start-stop operation. The test could then be used to look for new materials and coatings to ensure they would last the life-cycle of the vehicle and not become prematurely degraded, causing more emissions or engine repair costs. Ultimately, the project could be key to the way that future materials are chosen for our vehicles because the methodology simulates real engine driving conditions and would form part of automotive material testing standards.