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📦 归档：唐磊输出的环路车检器 KiCad 工程统一移入 pcb/ 目录

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2026-08-21 18:18:38 +08:00
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<!doctype html>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>环路车检器：检测方法推荐 + 原理图</title>
<style>
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body {
margin: 0;
background: var(--bg);
color: var(--fg);
font: 14px/1.4 ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
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<main>
<!-- ============ 图1：检测方法对比推荐 ============ -->
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<text x="20" y="34" class="title">环路车检器 · 检测方法对比与选型推荐</text>
<text x="20" y="56" class="small">选型核心：灵敏度（能否测摩托/自行车）× 抗干扰（变频器/电力谐波）× 成本。结论先行：主推 ①LC振荡+频率计数；复杂电磁环境上 ④；高灵敏需求上 ②。</text>
<!-- 卡片1 -->
<rect x="24" y="80" width="288" height="440" rx="10" class="node neutral"/>
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<rect x="24" y="80" width="288" height="36" rx="10" fill="#16a34a"/>
<text x="168" y="104" text-anchor="middle" fill="#fff" font-size="14" font-weight="700">① LC振荡 + 频率计数 ★★★★★</text>
<text x="40" y="140" font-size="12.5" font-weight="600">原理</text>
<text x="40" y="158" class="tiny">车辆进入 → 线圈等效电感↓ →</text>
<text x="40" y="174" class="tiny">振荡频率↑ → MCU 定时器测频/测周期</text>
<text x="40" y="202" font-size="12.5" font-weight="600">灵敏度</text>
<text x="40" y="220" class="tiny">★★★☆ 轿车/SUV 稳定；调阈值可测摩托</text>
<text x="40" y="248" font-size="12.5" font-weight="600">抗干扰</text>
<text x="40" y="266" class="tiny">★★★ 配自适应阈值 + 频偏跟踪</text>
<text x="40" y="294" font-size="12.5" font-weight="600">成本</text>
<text x="40" y="312" class="tiny">低（MCU + 三极管/比较器即可）</text>
<text x="40" y="340" font-size="12.5" font-weight="600">适用</text>
<text x="40" y="358" class="tiny">主流道闸/停车场/流量计数，市场 90%</text>
<text x="40" y="396" font-size="12.5" font-weight="600">要点</text>
<text x="40" y="414" class="tiny">周期法优于计数法：低速/停留不丢车</text>
<text x="40" y="430" class="tiny">回差阈值防抖动；基准慢速自适应抗温漂</text>
<text x="40" y="470" class="tiny" fill="#16a34a" font-weight="700">✅ 推荐主方案：成熟、稳定、成本最优</text>
<!-- 卡片2 -->
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<text x="470" y="104" text-anchor="middle" class="label">② PLL 锁相 / 相位比较 ★★★★</text>
<text x="342" y="140" font-size="12.5" font-weight="600">原理</text>
<text x="342" y="158" class="tiny">PLL 锁定振荡信号，车辆引起</text>
<text x="342" y="174" class="tiny">相位/频率误差 → 输出误差电压</text>
<text x="342" y="202" font-size="12.5" font-weight="600">灵敏度</text>
<text x="342" y="220" class="tiny">★★★★★ 可测自行车/电动车/行人拖车</text>
<text x="342" y="248" font-size="12.5" font-weight="600">抗干扰</text>
<text x="342" y="266" class="tiny">★★★ 环路锁定本身有滤波作用</text>
<text x="342" y="294" font-size="12.5" font-weight="600">成本</text>
<text x="342" y="312" class="tiny">中（PLL IC 或 MCU 内置 PLL 外设）</text>
<text x="342" y="340" font-size="12.5" font-weight="600">适用</text>
<text x="342" y="358" class="tiny">混行车道、ETC 车道、摩托车检测</text>
<text x="342" y="396" font-size="12.5" font-weight="600">要点</text>
<text x="342" y="414" class="tiny">环路带宽要窄：抗抖但响应慢，需折中</text>
<text x="342" y="430" class="tiny">适合与 ① 组合做双通道校验</text>
<text x="342" y="470" class="tiny" fill="#0f766e" font-weight="700">✅ 高灵敏场景备选</text>
<!-- 卡片3 -->
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<text x="772" y="104" text-anchor="middle" class="label">③ 电桥阻抗检测 ★★</text>
<text x="644" y="140" font-size="12.5" font-weight="600">原理</text>
<text x="644" y="158" class="tiny">环路与参考臂构成平衡电桥，</text>
<text x="644" y="174" class="tiny">车辆使阻抗失衡 → 输出失调电压</text>
<text x="644" y="202" font-size="12.5" font-weight="600">灵敏度</text>
<text x="644" y="220" class="tiny">★★ 中低，依赖桥臂匹配精度</text>
<text x="644" y="248" font-size="12.5" font-weight="600">抗干扰</text>
<text x="644" y="266" class="tiny">★★ 温漂/老化使零位漂移严重</text>
<text x="644" y="294" font-size="12.5" font-weight="600">成本</text>
<text x="644" y="312" class="tiny">低（纯模拟）</text>
<text x="644" y="340" font-size="12.5" font-weight="600">适用</text>
<text x="644" y="358" class="tiny">早期产品 / 教学演示</text>
<text x="644" y="396" font-size="12.5" font-weight="600">要点</text>
<text x="644" y="414" class="tiny">需定期人工调零，现场维护成本高</text>
<text x="644" y="470" class="tiny" fill="#991b1b" font-weight="700">⚠️ 不推荐量产</text>
<!-- 卡片4 -->
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<text x="1074" y="104" text-anchor="middle" class="label">④ 多频扫频 + 自适应调谐 ★★★★</text>
<text x="946" y="140" font-size="12.5" font-weight="600">原理</text>
<text x="946" y="158" class="tiny">DDS/扫频实时搜索谐振点，</text>
<text x="946" y="174" class="tiny">自动调谐避开干扰频段（变频器/谐波）</text>
<text x="946" y="202" font-size="12.5" font-weight="600">灵敏度</text>
<text x="946" y="220" class="tiny">★★★★ 扫频带宽内全频段可调</text>
<text x="946" y="248" font-size="12.5" font-weight="600">抗干扰</text>
<text x="946" y="266" class="tiny">★★★★★ 变频器干扰场景的终极解</text>
<text x="946" y="294" font-size="12.5" font-weight="600">成本</text>
<text x="946" y="312" class="tiny">高（DDS/高精度 ADC + 算法）</text>
<text x="946" y="340" font-size="12.5" font-weight="600">适用</text>
<text x="946" y="358" class="tiny">工业区/充电桩/变频器密集场所</text>
<text x="946" y="396" font-size="12.5" font-weight="600">要点</text>
<text x="946" y="414" class="tiny">与 ① 兼容：频率计数做粗判，</text>
<text x="946" y="430" class="tiny">扫频谱特征做细判与干扰识别</text>
<text x="946" y="470" class="tiny" fill="#0f766e" font-weight="700">✅ 复杂电磁环境旗舰方案</text>
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<!-- ============ 图2：原理图 ============ -->
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<text x="20" y="34" class="title">环路车检器原理图 — LC 振荡 + 频率计数方案（推荐①）</text>
<text x="20" y="56" class="small">信号链：环形线圈 → 浪涌保护 → 匹配变压器 → 谐振/考毕兹振荡 → 比较器整形 → MCU 测频判车 → 光耦隔离 → 继电器输出</text>
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<text x="326" y="423" class="tiny">GND</text>
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<text x="26" y="643" class="tiny">GND（电源地）</text>
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<text x="110" y="252" text-anchor="middle" class="small">路面（切割槽）</text>
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<text x="110" y="472" text-anchor="middle" class="small">环形线圈 3~5 匝</text>
<text x="110" y="488" text-anchor="middle" class="tiny">L≈50~200μH（待现场验证）</text>
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<text x="228" y="313" text-anchor="middle" class="tiny">A</text>
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<text x="228" y="433" text-anchor="middle" class="tiny">B</text>
<rect x="250" y="262" width="96" height="200" rx="6" class="zone"/>
<text x="298" y="254" text-anchor="middle" class="tiny">浪涌保护</text>
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<path d="M241,428 H330" class="wire"/>
<!-- 双向TVS -->
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<text x="300" y="386" class="tiny">TVS1</text>
<!-- 压敏 -->
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<rect x="312" y="350" width="12" height="36" class="comp"/>
<text x="336" y="370" class="tiny">RV1</text>
<!-- ===== C. 匹配变压器 T1 ===== -->
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<text x="410" y="254" text-anchor="middle" class="tiny">T1 匹配变压器 1:1~1:2</text>
<!-- 初级 -->
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<path d="M370,398 V420" class="wire"/>
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<path d="M400,300 V430" class="wireb"/>
<!-- 次级 -->
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<path d="M424,420 H452 V410" class="wire"/>
<path d="M446,330 H458" class="comp"/>
<path d="M446,410 H458" class="comp"/>
<path d="M452,330 V410" class="wire"/>
<text x="478" y="368" class="tiny">C1 谐振电容</text>
<text x="478" y="382" class="tiny">100~470pF</text>
<!-- 谐振上端 → 基极耦合 -->
<path d="M424,320 H480 V336" class="wireb" marker-end="url(#ar2)"/>
<text x="446" y="306" class="tiny">Cc1 10pF</text>
<path d="M452,300 H464" class="comp"/>
<path d="M452,312 H464" class="comp"/>
<path d="M458,300 V312" class="wire"/>
<!-- 次级下端 → 地 -->
<path d="M424,420 V430" class="wire"/>
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<rect x="462" y="248" width="180" height="196" rx="6" class="zone"/>
<text x="552" y="240" text-anchor="middle" class="tiny">考毕兹振荡器（基极调谐）</text>
<!-- Rb1: VCC→基极 -->
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<rect x="474" y="252" width="12" height="34" class="comp"/>
<path d="M480,286 V300" class="wire"/>
<text x="440" y="272" class="tiny">Rb1 100k</text>
<!-- Rb2: 基极→地 -->
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<rect x="494" y="356" width="12" height="34" class="comp"/>
<path d="M500,390 V430" class="wire"/>
<text x="520" y="376" class="tiny">Rb2 47k</text>
<!-- C3: 基极→地 -->
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<path d="M500,352 H512" class="wire"/>
<path d="M501,352 V364" class="wire"/>
<path d="M506,352 V364" class="wire"/>
<path d="M501,364 H506" class="comp"/>
<path d="M501,392 H506" class="comp"/>
<path d="M506,364 V392" class="wire"/>
<path d="M506,392 V430" class="wire"/>
<text x="522" y="416" class="tiny">C3 100p</text>
<!-- Q1 NPN -->
<path d="M480,300 H500 V340" class="wire"/>
<circle cx="500" cy="342" r="2.4" class="compf"/>
<path d="M500,342 L516,314 V290" class="wire"/>
<path d="M500,342 L514,370 V390" class="wire"/>
<path d="M504,360 L514,354" class="comp"/>
<path d="M508,364 L518,358" class="comp"/>
<text x="540" y="336" class="tiny">Q1</text>
<text x="540" y="350" class="tiny">S9018</text>
<!-- Rc: VCC→集电极 -->
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<rect x="510" y="256" width="12" height="30" class="comp"/>
<path d="M516,286 V290" class="wire"/>
<text x="540" y="272" class="tiny">Rc 2.2k</text>
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<path d="M526,280 a6,6 0 0 0 0,12 a6,6 0 0 1 0,12 a6,6 0 0 0 0,12" class="comp"/>
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<path d="M526,322 H500 V336" class="wire"/>
<text x="540" y="306" class="tiny">Lx 谐振</text>
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<path d="M540,300 V308" class="wire"/>
<path d="M534,308 H546" class="comp"/>
<path d="M534,356 H546" class="comp"/>
<path d="M540,308 V356" class="wire"/>
<path d="M540,356 V430" class="wire"/>
<text x="560" y="336" class="tiny">C2 100p</text>
<!-- 输出耦合 Cc2 -->
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<path d="M548,284 H560" class="comp"/>
<path d="M548,296 H560" class="comp"/>
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<text x="556" y="276" class="tiny">Cc2</text>
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<text x="686" y="240" text-anchor="middle" class="tiny">U1 比较器（带回差）</text>
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<path d="M640,290 V310" class="wire"/>
<path d="M686,300 L706,330 L686,360 Z" class="comp"/>
<path d="M706,330 H750" class="wireb" marker-end="url(#ar2)"/>
<text x="712" y="322" class="tiny">+</text>
<text x="712" y="352" class="tiny">−</text>
<!-- Vref 分压 -->
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<rect x="662" y="380" width="12" height="26" class="comp"/>
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<text x="610" y="392" class="tiny">Vref 分压</text>
<text x="610" y="406" class="tiny">(R3/R4)</text>
<!-- 频率标注 -->
<text x="640" y="452" class="tiny">方波输出 f≈f₀</text>
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<text x="900" y="262" text-anchor="middle" class="label">MCU</text>
<text x="900" y="278" text-anchor="middle" class="tiny">STM32/GD32F103</text>
<text x="816" y="302" class="tiny">· 定时器输入捕获测周期</text>
<text x="816" y="322" class="tiny">· f = Fclk / period → Δf</text>
<text x="816" y="342" class="tiny">· 数字滤波 + 消抖</text>
<text x="816" y="362" class="tiny">· 灵敏度阈值(多档)判断</text>
<text x="816" y="382" class="tiny">· 存在/通过 状态机</text>
<text x="816" y="402" class="tiny">· 基准频率慢速自适应(抗温漂)</text>
<text x="816" y="422" class="tiny">· 继电器输出 + 自检/看门狗</text>
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<text x="1222" y="346" class="tiny">NC</text>
<text x="1222" y="304" class="tiny">COM</text>
<text x="1124" y="318" class="tiny">→ 道闸/PLC</text>
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<!-- ===== H. 电源 ===== -->
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<text x="30" y="580" class="tiny">电源与保护</text>
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<text x="190" y="618" class="tiny">TVS2 吸收浪涌</text>
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<!-- ===== 图例 ===== -->
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<text x="36" y="722" class="label">元件图例</text>
<text x="36" y="746" class="tiny">L 电感（线圈符号）</text>
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<text x="140" y="746" class="tiny">C 电容</text>
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<text x="244" y="746" class="tiny">R 电阻</text>
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<text x="340" y="746" class="tiny">TVS 双向</text>
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<text x="440" y="746" class="tiny">NPN 三极管</text>
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<text x="560" y="746" class="tiny">MOS</text>
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<text x="660" y="746" class="tiny">继电器</text>
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<text x="36" y="806" class="tiny">关键设计点：① 环路经匹配变压器隔离耦合，直连会受地环路干扰；② 谐振电容 C1 决定频段，频率 f₀≈1/(2π√(LC))；③ 灵敏度=Δf 阈值，建议多档可调 + 回差；④ 基准频率上电自学习 + 慢速跟踪，抗温漂；⑤ 输出必须光耦隔离，防浪涌反灌烧 MCU；⑥ 软件加看门狗，继电器粘连检测。</text>
<text x="36" y="830" class="tiny">⚠️ 数值为典型参考：线圈电感取决于尺寸/匝数/引线长度，谐振频率推荐 20~150kHz（越低抗干扰越差、灵敏度越高，需现场折中）。</text>
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