结论：坡道驻车考验的不是制动力大小，是失电和故障时还保不保持
电动轮椅在坡道上停车是日常工况——等红灯、开门、与人交谈、上下车。
这个工况的风险在于：一旦保持失效，轮椅会带着使用者溜下坡，而使用者往往来不及反应。
电动轮椅的驻车通常依靠电磁制动器（失电制动型） ——通电时松开，断电时靠弹簧抱死。
这个设计本身是安全导向的（失电即制动），但验证要覆盖几种情形：
正常驻车。 停止后制动器正常抱死。
断电驻车。 电池耗尽或电源故障时。
推行模式。 手动推行模式下制动器被解除，此时在坡道上是危险的。
故障情形。 控制器故障、制动器故障。
长时间保持。 长时间停放后是否仍然保持。
驻车的机理与薄弱点
| 环节 | 正常状态 | 薄弱点 |
|---|---|---|
| 电磁制动器 | 失电抱死 | 摩擦片磨损、油污 |
| 控制逻辑 | 停止后延时抱死 | 延时过长期间溜车 |
| 传动链 | 制动力传到车轮 | 离合、齿轮间隙 |
| 推行释放杆 | 手动释放制动 | 误置于释放位 |
| 电源 | 供电正常 | 电量耗尽 |
「推行释放杆误置于释放位」是实际发生的风险 ——护理者推行后忘记复位，使用者上车后在坡道上就没有驻车能力。
这个风险的防护应当包括：明显的位置标识、复位提示、或者释放状态下限制电动行驶。
验证的坡度设置
标称坡度。 产品标称可通行的坡度。
超出标称的坡度。 验证裕度。
实际环境的坡度。 无障碍坡道、人行道横坡、车库坡道。
横坡。 侧向倾斜时的驻车。
组合坡度。 纵坡加横坡。
「横坡上的驻车」容易被忽略 ——人行道往往有排水用的横坡，而横坡上驻车时，轮椅可能侧向滑移或转向。
各工况的验证
正常停车驻车。 在坡道上正常停止，验证保持。
带载驻车。 加载到最大使用者重量。
超载验证。 适当超出标称载荷验证裕度。
上坡方向与下坡方向。 两个方向分别验证。
断电驻车。 行驶中断电，验证能否停住且保持。
长时间保持。 保持规定时间后检查位移。
反复驻车。 多次驻车后的性能保持。
「行驶中断电」是需要专门验证的工况 ——不只是验证能停住，还要验证停止过程是否可控（急停可能导致前倾或倾翻）。
溜车的判定
位移的测量。 规定时间内的位移量。
判定阈值。 多少位移算失效。
蠕动与滑移的区别。 缓慢蠕动和突然滑移的性质不同。
观察时间。 保持多长时间。
温度的影响。 制动器发热后的保持能力。
「制动器发热后的保持」需要验证 ——连续下坡时制动器持续工作会发热，摩擦系数可能下降，此时的驻车能力应当验证。
推行模式的安全
手动推行模式解除了电磁制动，这是一个明确的风险点：
释放杆的位置标识。 状态要明显可见。
释放状态的提示。 声光提示或显示屏提示。
释放状态下的电动限制。 建议释放状态下不能电动行驶。
自动复位。 部分设计在开机时自动复位或提示。
坡道上的警告。 说明书中应当警告不要在坡道上使用推行模式。
「释放状态下限制电动行驶」是有效的防护 ——它既避免了释放状态下的驻车失效，也避免了制动器在释放状态下被电机拖动而磨损。
故障情形的验证
单一故障下的安全。 任一部件故障时是否仍安全。
控制器故障。 控制器失效时制动器应当抱死。
线路断开。 制动器供电线断开时应当抱死（失电制动的优点）。
电池耗尽。 电量耗尽过程中的行为。
制动器本身故障。 摩擦片失效时的表现。
「电池耗尽过程中的行为」值得验证 ——电量不是突然归零的，在低电量状态下，控制器和制动器的行为应当是可预期的，而不是在坡道中途突然失去动力又未及时抱死。
说明与标识
最大通行坡度的说明。 明确标称值。
坡道使用的警告。 上下坡的正确方式。
推行模式的警告。 坡道上的禁用。
驻车的提示。 停车后确认驻车。
低电量的警告。 低电量时避免上坡。
定期检查的提示。 制动器的检查和保养。
「低电量时避免上坡」的警告很必要 ——上坡耗电快，低电量时上坡可能在坡中途耗尽电量，这是危险的情形。
常见的准备不足
信息不全。 材料、工艺、使用环境的信息缺失，导致方案设计缺乏依据。
样品不具代表性。 试制样品或挑选样品，与量产状态有差距。
条件未明确。 测试条件没说清楚，数据的适用范围就不明确。
只看初始值。 忽略了环境和时间作用后的性能变化。
项目不完整。 遗漏了必要的项目，提交时才发现。
这五项在实际委托中出现频率较高，建议在项目启动时逐项确认，因为它们造成的返工成本远高于事前确认所花的时间。
数据的组织与保存
记录的完整性。 条件、方法、设备、样品状态、实测值。
可追溯性。 数据与样品批次、生产批次的关联。
保存期限。 覆盖产品的生命周期。
检索的便利。 需要时能快速定位。
版本的管理。 数据更新时的版本控制。
建议建立统一的数据台账，记录每组数据的来源、条件、适用范围和有效期。数据积累起来之后，后续的产品开发和变更评估都能受益。
我们的做法
做坡道驻车验证时，我们会覆盖纵坡和横坡两种情形，因为实际环境中横坡普遍存在而容易被验证方案忽略。
「行驶中断电」我们作为专门工况验证 ——不只看能否停住，还观察停止过程是否可控，因为急停本身可能引发倾翻。
制动器发热后的保持能力我们建议一并验证 ——连续下坡后制动器温度升高，这时候的驻车能力与冷态可能不同。
推行释放杆的状态提示和释放状态下的电动限制，我们会在验证中专门确认 ——这是实际发生过问题的环节。
如果你的电动轮椅需要安排坡道驻车相关的验证，可以把制动方案和控制逻辑发过来一起定方案，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见电动轮椅检测，案例见案例。
English version
Conclusion. Parking a powered wheelchair on a slope is an everyday situation: waiting at a crossing, opening a door, talking to someone, getting in or out of a vehicle. Its risk is that once holding fails, the chair runs away downhill with the user aboard, and the user frequently cannot react in time. Powered wheelchairs generally park using electromagnetic brakes of the fail-safe type, released when energised and clamped by spring when de-energised. That design is inherently safety-oriented, since loss of power means braking, while verification must cover several situations. Normal parking, where the brake clamps properly after stopping. Parking without power, where the battery is exhausted or the supply fails. Free-wheel mode, where the brake is released for manual pushing, which is hazardous on a slope. Fault conditions, covering controller and brake faults. And prolonged holding, covering whether it still holds after standing for a long period.
The mechanism and its weak points. The electromagnetic brake clamps when de-energised, with wear and contamination of the friction material as weak points. The control logic clamps after a delay once stopped, with an overlong delay allowing run-away in the interval. The drive train transmits braking to the wheels, with clutches and gear backlash as weak points. The free-wheel lever releases the brake manually, with inadvertent selection as the weak point. And the power supply feeds the system, with exhaustion as the weak point. A free-wheel lever left in the released position is a risk that genuinely occurs: a carer pushes the chair and forgets to reset it, and the user boards with no parking capability on a slope. Guarding against it should include conspicuous position marking, a reset prompt, or inhibiting powered driving while released.
Setting test gradients. The stated gradient the product claims to negotiate. Gradients beyond it, to verify margin. Gradients from real environments, covering access ramps, pavement cross-falls and car park ramps. Cross-slopes, covering parking while laterally inclined. And combined gradients, with longitudinal and lateral together. Parking on a cross-slope is readily overlooked: pavements commonly carry a cross-fall for drainage, and on one the chair may slide sideways or turn.
Verifying each situation. Normal parking, stopping on a slope and verifying that it holds. Loaded parking at maximum user mass. Overload verification, somewhat beyond the stated load, to verify margin. Uphill and downhill directions, verified separately. Parking without power, cutting power while moving and verifying that it stops and holds. Prolonged holding, checking displacement after a specified period. And repeated parking, verifying retention after many cycles. Cutting power while moving deserves specific verification: not only whether it stops, but whether the stopping is controlled, since an abrupt stop may pitch the chair forward or tip it.
Judging run-away. Measure displacement over a specified period. Set a threshold for what counts as failure. Distinguish creep from slip, since slow creep and sudden slip differ in nature. Set the observation period. And consider temperature, covering holding capability after the brake has warmed. Holding after the brake warms needs verification: continuous descent keeps the brake working and heats it, the friction coefficient may fall, and parking capability in that state should be verified.
Safety in free-wheel mode. Manual pushing releases the electromagnetic brake, which is a definite risk point. Mark the lever position so the state is conspicuous. Indicate the released state audibly, visually or on the display. Inhibit powered driving while released, which is advisable. Reset automatically, as some designs do at power-up, or prompt for it. And warn in the instructions against using free-wheel mode on slopes. Inhibiting powered driving while released is effective protection: it prevents both parking failure in the released state and wear on the brake from being driven by the motor while released.
Verifying fault conditions. Single-fault safety, covering whether the chair remains safe with any one component failed. Controller failure, where the brake should clamp. Open circuit, where the brake should clamp if its supply is interrupted, which is the merit of fail-safe braking. Battery exhaustion and the behaviour as it occurs. And brake failure itself, covering what happens when the friction material fails. Behaviour during battery exhaustion is worth verifying: charge does not fall to nothing instantly, and at low charge the controller and brake should behave predictably rather than losing drive midway up a slope without clamping promptly.
Instructions and marking. State the maximum negotiable gradient explicitly. Warn about slope use, covering the correct way to ascend and descend. Warn against free-wheel mode on slopes. Prompt confirmation of parking after stopping. Warn against ascending at low charge. And prompt periodic inspection and maintenance of the brake. Warning against ascending at low charge is necessary: ascending consumes charge quickly, and starting a climb at low charge may exhaust it partway up, which is hazardous.
How we handle it. For slope parking verification we cover both longitudinal and cross-slopes, since cross-falls are widespread in real environments while readily omitted from test programmes. We verify power loss while moving as a specific situation, observing not only whether it stops but whether the stop is controlled, since an abrupt stop may itself cause tipping. We suggest verifying holding capability with the brake warm, since after a continuous descent the brake's temperature rises and its parking capability may differ from cold. And we confirm the free-wheel lever's state indication and the inhibition of powered driving while released, this being a point where problems have genuinely occurred.
If your powered wheelchair needs slope parking verification, send us the braking arrangement and control logic and we will settle the approach: +86 132 4819 8029.