vibration

Articles, guides, and products tagged "vibration" — a combined view of every catalogue resource on this topic.

User guide

Display and HMI engineering for electric scooters: sunlight-readability photometry (CR, cd/m², transflective LCD), glanceability ergonomics (ISO 15008, NHTSA 2-glance ≤ 2 s / 12 s, Fitts' law, Frutiger/DIN 1450), adaptive brightness (Weber-Fechner, PWM flicker per IEEE 1789-2015), environmental robustness (IP66, ISO 16750-3 vibration, IEC 60068 thermal −20…+70 °C), EMC (CISPR 14-1, ECE R10) and functional safety (IEC 62368-1, ISO 13849-1)

An engineering deep-dive into the one bidirectional channel between e-scooter and rider — paired with the introductory survey «Display, throttle, and error codes» (parts/display-throttle-error-codes): matrix physics (TN LCD with 90° twisted nematic vs IPS LCD with in-plane molecular switching vs OLED with organic electroluminescence via electron-hole recombination vs E-paper with electrophoretic ink); sunlight readability as a photometric problem (contrast ratio CR=(L_max+L_amb·R)/(L_min+L_amb·R) with ambient reflection, why a 250 cd/m² LCD against 100 000 lx direct sun drops to CR=1.05:1 without an anti-reflective coating, and transflective LCD as a hybrid with ambient backlight); glanceability as safety-critical ergonomics (ISO 15008:2017 in-vehicle visual presentation with minimum character-height-to-distance ratio 1:200, ISO 9241-303:2011 visual ergonomics, NHTSA Driver Distraction Guidelines 2013 + SAE J2364 2-glance principle ≤2 s single + ≤12 s total, Fitts' law T=a+b·log₂(D/W+1) for button-reach time, sans-serif Frutiger 1976 + DIN 1450:2013 Schriften — Leserlichkeit, kerning, x-height ≥60 % cap-height); adaptive brightness (Weber-Fechner logarithmic perception ΔI/I=const, ambient light sensor 0.01-100 000 lx, PWM dimming for LCD backlight with flicker frequency ≥1 kHz per IEEE 1789-2015 No-Observable-Effect threshold); environmental robustness (IEC 60529:2013 IP66 ingress dust-tight+powerful jets, ISO 16750-3:2012 road vehicle mechanical loads 10-2000 Hz random vibration, IEC 60068-2-1/-2 temperature −20…+70 °C cycling, IEC 60068-2-27 mechanical shock 1500g 0.5 ms half-sine, IEC 60068-2-30 damp heat 25/40 °C 95 % RH, ASTM B117-19 salt spray 5 % NaCl 35 °C 96 h); EMC (CISPR 14-1:2020 household-appliance emission, UNECE Regulation 10 Rev 6:2017 vehicle EMC 30 MHz-1 GHz radiated, ferrite chokes for PWM-backlight harmonic suppression); functional safety (IEC 62368-1:2018 hazard-based safety engineering with ES1/ES2 energy-source classes + PS1/PS2 power source + MS1/MS2 mechanical source, ISO 13849-1:2015 PL_d performance level so that display failure does NOT cause throttle/brake loss); and the full comparison matrix of 12 standards (ISO 15008 + ISO 9241-303 + ISO 9241-11 + NHTSA/SAE J2364 + IEEE 1789-2015 + IEC 62368-1 + IEC 60529 + IEC 60068-2 + ISO 16750-3 + CISPR 14-1 + UNECE R10 + ISO 13849-1).

18 min read

User guide

Riding on difficult road surfaces on an e-scooter: contact-patch physics on cobblestones, tram tracks, gravel, wet leaves, painted lines and expansion joints

Six disciplinary micro-environments that no existing guide covers individually: cobblestones (Belgian setts, granite slabs, round river-rock cobbles — 5–30 Hz vibration, micro-loss-of-contact, μ_wet 0.3–0.4, sweet-spot speed, line between joints); tram tracks (wheel-slot 35–45 mm wide × 38–58 mm deep for standard 1435 mm gauge, crossing angle ≥45° mandatory, convex rail head, wet-rail μ 0.05–0.10 — worse than ice, four failure modes); gravel and sand (two-layer dynamics, front-wheel plowing effect, amplified slip-angle in cornering); wet leaves (μ ~0.1 as on ice); painted lines (μ_wet ↓ ×3 to 0.2–0.3, metal manhole covers and plates even worse); expansion joints and poor patch repairs (parallel-grooves like miniature rails, step-transitions deflecting the front wheel, sunken utility covers 2–5 cm below grade). The common denominator is the 5–15 cm² contact patch on an e-scooter tire and the three types of its failure: material μ failure, geometric trap-or-deflect, kinetic momentary contact loss from vibration. Defensive cross-cut: tire-pressure adjustment 30–35 PSI vs 40–45, active stance with soft knees and elbows for 2–3 cm of vertical absorption, weight bias (rear over bumps, forward over slick patches), 60–75 % of normal speed, rear-brake-first on slippery surfaces. Especially relevant for Ukrainian cities with cobblestoned historical centres (Lviv, Kyiv-Podil, Kamianets-Podilskyi) and tram networks (Kyiv, Lviv, Kharkiv, Dnipro, Odesa, Mariupol). ENG-first sources: Edinburgh/Vienna/Toronto tram-track cyclist injury studies, AASHTO/TRB pavement marking BPN friction standards, Paris-Roubaix vibration analysis (cycling-physics engineering refs), wheel-rail interface μ literature, Schwalbe/Vittoria tire pressure technical guides, ASCE bridge expansion joint design, OSM surface= + smoothness= tag refs, League of American Bicyclists wet-leaves safety briefings.

14 min read