样机阶段该先测哪几项

结论：优先做那些「如果不合格，改动成本最大」的项目

样机阶段不可能把所有项目都做一遍，资源有限，要选择做哪些。

选择的依据不是项目的重要性，而是「如果这一项不合格，整改的代价有多大」。

代价大的项目优先做，因为早发现才有时间和空间调整；代价小的项目可以放到后面，即使定型检验时才发现，改起来也不难。

按这个逻辑排序，样机阶段的测试资源就能用在刀刃上。

整改代价的判断

不合格项	整改涉及	代价
车架强度不足	结构、模具、工装	很大
EMC 不合格	电路、结构、屏蔽	大
电气安全不合格	电路、绝缘、结构	大
稳定性不足	几何布局、重心	大
疲劳寿命不足	结构、材料	大
制动效能不足	制动系统选型	中
阻燃不合格	材料更换	中
标识不符	印刷或铭牌	小
说明书内容	文档修订	小

从表里能看出：涉及结构、模具、电路的项目代价大，这些应当优先在样机阶段验证。

值得优先做的项目

第一优先：结构强度与稳定性。

静载强度、关键部位的受力、以及各方向的稳定性。这些不合格意味着结构要改，而结构改动牵连模具、工装、装配。

第二优先：电气安全与电磁兼容的摸底。

电动产品的这两项，整改涉及电路板改版、增加滤波、改进屏蔽和接地，每一项都涉及硬件改动和重新打样。

第三优先：疲劳耐久的启动。

不是因为整改代价大（虽然也不小），而是因为周期长 ——现在不启动，结果出来时已经影响进度。

第四优先：关键功能的验证。

制动、折叠、调节机构的功能与可靠性。

第五优先：材料相关的项目。

阻燃、生物相容性。整改是换材料，代价中等，但换材料可能影响其他性能，所以也不宜太晚。

简化方法的使用

样机阶段的测试可以简化，只要能回答关键问题：

静载试验可以简化加载方式。 用简易夹具、按标准的载荷值加载，观察变形和失效。

稳定性可以用简易倾斜台。 不必用完整的试验装置。

EMC 可以做预扫。 在简易环境中做发射预扫，看是否有明显超标的频点。

电气安全可以做关键项。 漏电流、耐压这两项用基本设备就能做初步判断。

疲劳可以用局部加载。 对怀疑的薄弱部位单独做循环加载。

简化方法的数据不能用于申报，但能回答「有没有明显问题」这个问题，这正是样机阶段需要的。

EMC 预扫的价值

这一项值得单独说，因为它的性价比较高：

发射预扫成本不高，在简易环境中就能看出是否有明显超标的频点。

发现问题时整改空间大。 样机阶段可以改电路布局、加滤波元件、改进接地，而定型后这些改动都很麻烦。

能指导设计。 预扫的结果能说明问题出在哪个频段，进而指向可能的源（时钟、开关电源、电机驱动）。

抗扰度也可以做初步测试。 用简易的干扰源看设备是否容易受影响。

建议电动产品在样机阶段做一次 EMC 预扫，这是投入产出比较高的一项早期验证。

结构验证的重点

薄弱部位的识别。 通过计算或经验判断哪些部位应力集中。

针对性加载。 对薄弱部位做重点验证。

失效模式的观察。 加载到失效，看在哪里失效、怎么失效。这个信息对改进的价值大于「合格与否」。

变形量的测量。 即使不失效，变形量大的部位也是改进的对象。

焊缝与连接处的检查。 这些位置是常见的失效起点。

「加载到失效」在样机阶段是有价值的做法。 正式检验只需要判断是否通过，而样机阶段更需要知道余量有多大、薄弱点在哪里。

用户试用的配合

除了实验室测试，样机阶段的用户试用能发现另一类问题：

实际使用中的不便。 操作是否顺手、调节是否方便。

未预料的使用方式。 使用者可能怎么用。

舒适性问题。 长时间使用的感受。

可维护性。 日常清洁和维护是否方便。

试用中发现的问题往往是实验室测试发现不了的，两者互补。

数据的后续价值

样机阶段的数据不只用于当前的判断：

作为设计验证的证据。 技术文件中的设计输入输出验证。

作为正式检验的预期。 知道大致的数值，正式检验时异常值容易识别。

作为改进的基线。 改进前后的对比。

作为风险分析的输入。 发现的失效模式纳入风险文件。

作为后续产品的参考。 同类产品开发时的经验。

建议样机阶段的测试也做规范的记录 ——条件、方法、数据、结论。记录规范的数据，后续才用得上。

样机与量产的差异

样机测试的数据要考虑样机与量产品的差异：

工艺差异。 样机可能是手工装配或简易工装，量产用正式工装。

材料差异。 样机可能用替代材料或不同批次。

零件差异。 样机零件可能是快速成型或机加工，量产是模具件。

一致性差异。 样机是个别产品，量产有批次分散。

所以样机数据偏向于「这个设计能不能做到」，而不是「量产产品能做到」。 判断时要留出余量。

建议样机测试的结果与规格限值之间留出明显的余量，因为量产的分散性会消耗一部分余量。

测试计划的组织

样机阶段的测试建议做一份简单的计划：测哪几项、为什么测这几项、用什么方法、预期什么结果、以及不合格时的应对方向。

「不合格时的应对方向」提前想一下有价值，因为它能帮助判断这项测试是不是真的需要现在做——如果不合格也没有调整空间，早测的意义就不大。

我们的做法

我们可以承接样机阶段的摸底测试，方法可以按委托方的需要简化，目的是快速回答问题而不是出具正式报告。 这类测试周期短、成本低。

对于电动轮椅类产品，我们建议样机阶段优先做结构强度、稳定性、以及 EMC 预扫 ——这三项如果有问题，整改涉及的面最广。

疲劳试验建议在样机阶段启动，即使样机还不是最终状态，得到的寿命数据对判断设计余量有参考价值，而且能提前暴露薄弱部位。

如果你有样机需要做摸底测试，想先确定测哪几项，可以把产品方案和关注点发过来一起讨论，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见手动轮椅检测与电动轮椅检测，案例见案例。

English version

Conclusion. Testing every item at prototype stage is impossible, so with limited resources the question is which to choose. The basis is not how important an item is but how expensive remediation would be if it failed. Do the expensive ones first, because finding them early leaves time and room to adjust; the cheap ones can wait, since even discovering them at type testing leaves them easy to fix. Ordering by that logic puts prototype test resources where they count.

Judging remediation cost. Inadequate frame strength involves structure, tooling and fixtures, at very high cost. Electromagnetic compatibility failure involves circuits, structure and screening, at high cost. Electrical safety failure involves circuits, insulation and structure, at high cost. Inadequate stability involves geometry and centre of gravity, at high cost. Inadequate fatigue life involves structure and materials, at high cost. Inadequate braking involves the braking system selection, at moderate cost. Flammability failure involves material substitution, at moderate cost. Marking nonconformity involves printing or nameplates, at low cost. And instruction content involves document revision, at low cost. Items involving structure, tooling and circuits cost the most and should be verified first at prototype stage.

Items worth doing first. First, structural strength and stability, covering static strength, loading at critical points and stability in each direction; failure here means changing the structure, which drags in tooling, fixtures and assembly. Second, a survey of electrical safety and electromagnetic compatibility for powered products, since remediation involves board revisions, added filtering and improved screening and earthing, each requiring hardware change and new prototypes. Third, starting fatigue durability, not because remediation is expensive, though it is, but because the duration is long and starting late means results arrive too late. Fourth, verification of key functions, covering braking, folding and adjustment mechanisms. And fifth, material-related items covering flammability and biocompatibility; remediation means changing material at moderate cost, though a material change may affect other properties, so it should not be left too late either.

Using simplified methods. Prototype testing can be simplified as long as it answers the key question. Static loading can use simple fixtures, applying standard load values and observing deformation and failure. Stability can use a simple tilt platform rather than a complete test rig. Electromagnetic emissions can be pre-scanned in a simple environment to see whether any frequencies are clearly over limit. Electrical safety can cover key items, with leakage and dielectric strength giving a preliminary judgement using basic equipment. And fatigue can use local loading, cycling a suspected weak point alone. Data from simplified methods cannot support submission, but they answer whether an obvious problem exists, which is what the prototype stage needs.

The value of electromagnetic pre-scanning. This deserves separate mention for its cost-effectiveness. Emission pre-scanning is inexpensive and reveals clearly over-limit frequencies even in a simple environment. Problems found leave room to act, since at prototype stage circuit layout can change, filter components can be added and earthing improved, all awkward once the design is frozen. It guides design, since the results indicate the frequency band involved and hence the likely source, whether clocking, switching supply or motor drive. And immunity can be surveyed preliminarily with simple disturbance sources. Run an electromagnetic pre-scan on powered products at prototype stage; it is among the highest-return early verifications.

Focus in structural verification. Identify weak points through calculation or experience, determining where stress concentrates. Load them specifically for targeted verification. Observe the failure mode by loading to failure, noting where and how it fails; that information is more valuable for improvement than a pass or fail. Measure deformation, since even without failure, areas deforming substantially are candidates for improvement. And inspect welds and joints, which are common failure origins. Loading to failure is valuable at prototype stage: formal testing only needs a verdict, while prototype work needs to know how much margin exists and where the weak points are.

Complementing with user trials. Alongside laboratory testing, user trials at prototype stage reveal a different class of problem. Inconvenience in use, covering whether operation is natural and adjustment straightforward. Unanticipated use, revealing how users may actually use it. Comfort over prolonged use. And maintainability, covering ease of cleaning and servicing. Problems found in trials are typically ones laboratory testing cannot find, and the two complement one another.

Later value of the data. Prototype data serve beyond the immediate judgement. As design verification evidence within the technical documentation. As expected values for formal testing, so that anomalies stand out. As a baseline for improvement, comparing before and after. As input to risk analysis, with discovered failure modes entering the risk file. And as reference for later products developing similar designs. Record prototype testing properly, covering conditions, methods, data and conclusions; only properly recorded data can be used later.

How we handle it. We can perform prototype survey testing, with methods simplified to the client's needs, aiming at quick answers rather than formal reports. Such testing is short and inexpensive. For powered wheelchairs we suggest prioritising structural strength, stability and electromagnetic pre-scanning at prototype stage, the three whose failure has the widest remediation consequences. We suggest starting fatigue testing at prototype stage even where the prototype is not in final condition, since the life data inform judgements about design margin and expose weak points early.

Send us your product concept and concerns and we will work out which items to test. Phone or WeChat: +86 132 4819 8029.