215 lines
10 KiB
Python
215 lines
10 KiB
Python
# -*- coding: utf-8 -*-
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"""关节电机力矩与负载能力校核。
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与旧版的区别（这些是旧版实际出错的地方）：
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1. 拓扑。旧版把关节表手抄成 "J3 肘俯仰 / J4 前臂自转 / J5 腕俯仰 / J6 夹爪"，
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并据此虚构了一个夹爪机构和 135mm 大臂——与 human_layout.py 的实际拓扑
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（J3 大臂自转 / J4 肘俯仰 / J6 腕自转）完全不符，整份报告的结论都是错的。
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本版不再复制拓扑：零件表、关节轴、运动学链全部复用 strength_check，
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而 strength_check 的轴又直接来自 human_layout，单一事实源。
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2. 力臂。旧版把每个关节的质量与力臂写成硬编码常数（J2 = 1.75kg @ 464mm），
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几何一改就失效且不会报错。本版按每个零件的真实质心、在可达姿态网格上
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搜索最大重力力矩。
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3. 惯量。旧版用一组手填的 kg·m²。本版按 Σm·d²（对关节轴的平行轴距离）
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在同一姿态网格上取最大值。零件自身转动惯量未计入，对大臂量级的关节
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是小修正，已在报告中标注。
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电机参数：仓库内没有原始数据手册，以下为工程假定，可用环境变量覆盖。
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ARMT_CONT 连续额定输出力矩 (N·m)
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ARMT_PEAK 峰值堵转输出力矩 (N·m)
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ARMT_ALLOW 封闭塑料外壳热衰减后的许用连续力矩 (N·m)
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ARMT_ALPHA 角加速度 (rad/s²)
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ARMPAY 末端负载 (kg)
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输出：docs/torque_balance.json + docs/torque_report.md
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"""
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import io
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import json
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import math
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import os
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import sys
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sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
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try:
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sys.stdout.reconfigure(encoding="utf-8")
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except Exception:
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pass
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import human_layout as HL
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from armcore import DOCS
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import strength_check as SC
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G = 9.81
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T_CONT = float(os.environ.get("ARMT_CONT", "2.5"))
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T_PEAK = float(os.environ.get("ARMT_PEAK", "8.0"))
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T_ALLOW = float(os.environ.get("ARMT_ALLOW", "2.0"))
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ALPHA = float(os.environ.get("ARMT_ALPHA", "5.0"))
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PAYLOAD = float(os.environ.get("ARMPAY", "0.5"))
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# 关节名与轴向，全部取自 human_layout（不手抄）
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JOINT_CN = {t[0]: t[1] for t in HL.JOINTS}
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JOINT_D = {t[0]: t[3] for t in HL.JOINTS}
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def _axis_kind(tag):
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d = JOINT_D[tag]
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if abs(d[2]) == 1:
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return "roll(绕Z)"
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if abs(d[0]) == 1:
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return "roll(绕X)"
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return "pitch(绕Y)"
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def analyze(payload_kg=PAYLOAD):
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parts = SC.part_table(payload_kg)
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jl = SC.joint_loads(parts)
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jl0 = SC.joint_loads(SC.part_table(0.0)) # 去掉末端负载，用于反推负载能力
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masses = {"J%d" % j: sum(m for _, m, _, g in parts if g >= j) for j in range(1, 7)}
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arm_mass = {k: v - payload_kg * 1000.0 for k, v in masses.items()}
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res = {"assumptions": {
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"motor": "60mm 方形标准关节电机模组，2 级行星减速",
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"T_cont_Nm": T_CONT, "T_peak_Nm": T_PEAK, "T_allow_Nm": T_ALLOW,
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"alpha_rad_s2": ALPHA, "payload_kg": payload_kg,
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"note": "电机参数为工程假定，仓库内无数据手册；结论对此敏感，见报告第 4 节",
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}, "joints": {}}
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for j in range(1, 7):
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tag = "J%d" % j
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r = jl[tag]
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tau_g = r["tau"] / 1000.0 # N*m，重力
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tau_dyn = r["I"] * ALPHA # N*m，惯性
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tau_g_arm = jl0[tag]["tau"] / 1000.0 # 去掉负载后的重力力矩
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req_static = tau_g
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req_peak = tau_g + tau_dyn
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res["joints"][tag] = {
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"cn": JOINT_CN[tag], "axis": _axis_kind(tag),
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"distal_mass_kg": round(masses[tag] / 1000.0, 3),
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"arm_mass_kg": round(arm_mass[tag] / 1000.0, 3),
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"weight_N": round(r["F"], 1),
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"reach_tip_mm": round(r["Lp"], 0),
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"tau_gravity_Nm": round(tau_g, 3),
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"tau_gravity_arm_only_Nm": round(tau_g_arm, 3),
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"I_distal_kgm2": round(r["I"], 5),
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"tau_dynamic_Nm": round(tau_dyn, 3),
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"tau_required_static_Nm": round(req_static, 3),
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"tau_required_peak_Nm": round(req_peak, 3),
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"duty_vs_Tcont_pct": round(100.0 * req_static / T_CONT, 1),
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"duty_vs_Tallow_pct": round(100.0 * req_static / T_ALLOW, 1),
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"peak_margin_x": round(T_PEAK / req_peak, 2) if req_peak > 1e-3 else None,
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"status": "OK" if (req_static <= T_ALLOW and req_peak <= T_PEAK) else "OVERLOAD",
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}
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return res, jl0, jl
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def max_payload(res):
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"""在许用连续力矩下，末端还能带多少 kg（按各关节取最小）。
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线性化：tau_g(p) ≈ tau_g_arm + p·g·L。用的是该关节实测的最大 TCP 力臂，
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即最不利姿态下的力臂。
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"""
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out = {}
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for tag, d in res["joints"].items():
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L = d["reach_tip_mm"] / 1000.0
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if L <= 0:
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out[tag] = None
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continue
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head = T_ALLOW - d["tau_gravity_arm_only_Nm"]
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out[tag] = round(max(head, 0.0) / (G * L), 3) if head > 0 else 0.0
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return out
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def generate_report(res, mp):
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L = []
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L.append("# 6 自由度机械臂 · 关节电机力矩与负载能力校核\n")
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a = res["assumptions"]
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L.append("## 1. 前提\n")
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L.append("- 驱动：%s" % a["motor"])
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L.append("- 连续额定输出力矩 `T_cont` = %.2f N·m；峰值堵转 `T_peak` = %.2f N·m"
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% (a["T_cont_Nm"], a["T_peak_Nm"]))
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L.append("- 封闭打印外壳热衰减后许用连续力矩 `T_allow` = %.2f N·m；末端负载 %.2f kg；"
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"角加速度 %.1f rad/s²" % (a["T_allow_Nm"], a["payload_kg"], a["alpha_rad_s2"]))
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L.append("- **%s**\n" % a["note"])
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L.append("载荷模型：每个零件按网格体积加权质心定位，随姿态做刚体变换，在可达姿态"
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"网格（俯仰轴取行程端点/中值，自转轴取 0/±60/±120/180°）上取重力力矩最大值。"
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"力矩为绕**关节自身轴**的分量——这才是电机要出的力。\n")
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L.append("## 2. 各关节校核结果\n")
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L.append("| 关节 | 名称 | 轴 | 以下质量(kg) | TCP力臂(mm) | 重力力矩(N·m) | 惯性力矩(N·m) | 峰值需求(N·m) | 负荷率(对T_allow) | 峰值裕度 | 判定 |")
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L.append("|:---:|:---|:---|---:|---:|---:|---:|---:|---:|---:|:---:|")
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for tag, d in res["joints"].items():
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L.append("| %s | %s | %s | %.2f | %.0f | **%.2f** | %.2f | %.2f | **%.0f%%** | %s | %s |"
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% (tag, d["cn"], d["axis"], d["distal_mass_kg"], d["reach_tip_mm"],
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d["tau_gravity_Nm"], d["tau_dynamic_Nm"], d["tau_required_peak_Nm"],
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d["duty_vs_Tallow_pct"],
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("%.2f×" % d["peak_margin_x"]) if d["peak_margin_x"] else "—", d["status"]))
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L.append("")
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L.append("## 3. 许用连续工况下的末端负载能力\n")
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L.append("去掉末端负载后各关节仍需 `tau_gravity_arm_only` 的重力力矩，余额除以该关节"
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"实测最大 TCP 力臂，即为还能挂的负载：\n")
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L.append("| 关节 | 仅臂身重力力矩(N·m) | 余额(N·m) | 可挂负载(kg) |")
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L.append("|:---:|---:|---:|---:|")
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for tag, d in res["joints"].items():
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head = T_ALLOW - d["tau_gravity_arm_only_Nm"]
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L.append("| %s | %.2f | %+.2f | %s |"
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% (tag, d["tau_gravity_arm_only_Nm"], head,
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("%.2f" % mp[tag]) if mp[tag] is not None else "—"))
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ok = [t for t, v in mp.items() if v is not None]
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worst = min(ok, key=lambda t: mp[t]) if ok else None
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if worst:
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L.append("")
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L.append("**整臂瓶颈：%s，可挂末端负载 %.2f kg。**\n" % (worst, mp[worst]))
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L.append("## 4. 结论要点\n")
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over = [t for t, d in res["joints"].items() if d["status"] == "OVERLOAD"]
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if over:
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L.append("- **超载关节：%s**。" % "、".join(over))
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for t in over:
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d = res["joints"][t]
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L.append(" - %s（%s）重力 %.2f N·m，超 `T_allow` %.0f%%；即使按峰值堵转算，"
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"裕度也只有 %s。" % (t, d["cn"], d["tau_gravity_Nm"],
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d["duty_vs_Tallow_pct"] - 100.0,
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("%.2f×" % d["peak_margin_x"]) if d["peak_margin_x"] else "—"))
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L.append("- 结论对电机参数高度敏感：若实际连续额定高于假定值，"
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"请用 `ARMT_CONT` / `ARMT_ALLOW` 覆盖后重跑本脚本。")
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else:
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L.append("- 全部关节在许用连续力矩内。")
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L.append("- 惯量按 Σm·d² 估，**未计入零件自身转动惯量**，对肩/肘是大臂量级的关节"
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"约低估一成，惯性力矩一栏应视为下限。")
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L.append("- 本版不含被动弹簧平衡。旧版报告提出的 J2 拉簧预补偿（2.48 N·m）在几何上"
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"**尚未实现**；若要保留该方案，需要在 P04/P05 之间增加拉簧连杆机构。")
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return "\n".join(L)
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def main():
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res, jl0, jl = analyze(PAYLOAD)
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mp = max_payload(res)
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io.open(DOCS + "/torque_balance.json", "w", encoding="utf-8").write(
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json.dumps(res, ensure_ascii=False, indent=2))
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io.open(DOCS + "/torque_report.md", "w", encoding="utf-8").write(generate_report(res, mp))
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print("末端负载 %.2f kg T_cont=%.2f T_allow=%.2f T_peak=%.2f alpha=%.1f\n"
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% (PAYLOAD, T_CONT, T_ALLOW, T_PEAK, ALPHA))
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print("%-4s %-8s %-12s %8s %8s %8s %9s %8s %s"
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% ("关节", "名称", "轴", "重力N·m", "惯性N·m", "峰值N·m", "负荷率", "峰值裕度", "判定"))
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for tag, d in res["joints"].items():
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print("%-4s %-8s %-12s %8.2f %8.2f %8.2f %8.0f%% %8s %s"
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% (tag, d["cn"], d["axis"], d["tau_gravity_Nm"], d["tau_dynamic_Nm"],
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d["tau_required_peak_Nm"], d["duty_vs_Tallow_pct"],
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("%.2fx" % d["peak_margin_x"]) if d["peak_margin_x"] else "-",
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d["status"]))
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print("\n许用连续力矩下可挂末端负载 (kg):")
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for tag in res["joints"]:
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print(" %-4s %s" % (tag, ("%.2f" % mp[tag]) if mp[tag] is not None else "—"))
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ok = [t for t, v in mp.items() if v is not None]
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if ok:
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w = min(ok, key=lambda t: mp[t])
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print(" 整臂瓶颈 %s -> %.2f kg" % (w, mp[w]))
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print("\n已写出 docs/torque_balance.json + docs/torque_report.md")
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sys.stdout.flush()
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if __name__ == "__main__":
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main()
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os._exit(0)
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