Sidewalk Delivery Robot Concept Draft
A small autonomous delivery robot concept for a campus cafe, designed to move sealed drinks or food across sidewalks and campus paths with a modest payload, short-range battery power, and a compact footprint.
Overview
This concept is a compact electric delivery robot for a campus cafe. It carries insulated orders at walking speed, follows planned routes, and is meant for smooth sidewalks, curb cuts, and low-speed shared pedestrian areas.
The main goals are simple: keep the payload secure, stay visible to pedestrians, fit through campus paths and door approaches, and use a battery setup that can cover a typical shift with charging between runs.
Primary users
Cafe staff, campus delivery staff, and route supervisors
Cafe staff, campus delivery staff, and route supervisors
Operating pace
Low-speed sidewalk travel, stopping often near people
Low-speed sidewalk travel, stopping often near people
Main risk
Pedestrian interaction, weather exposure, and curb handling
Pedestrian interaction, weather exposure, and curb handling
Key specs
| Spec | Target | Notes |
|---|---|---|
| Overall size | approx. 30 in wide × 24 in deep × 42 in tall | Compact enough for sidewalks and docking near counters |
| Weight | approx. 80–120 lb empty | Depends on battery size, enclosure, and frame material |
| Payload capacity | approx. 20 lb | Estimated for food, drinks, packaging, and accessories |
| Range | approx. 4–8 miles per charge | 6 miles is the planning target; terrain and payload will change this |
| Top speed | approx. 3–5 mph | Walking-speed operation for shared pedestrian areas |
| Run time | approx. 3–6 hours of mixed use | Depends on stops, route length, and battery health |
| Drive system | Electric battery drive, dual-wheel or four-wheel base | Motor and gearbox choice should be confirmed by a professional |
| Materials | Aluminum frame, polymer body panels, rubber tires, steel hardware | Chosen for low weight, durability, and easy maintenance |
| Power | approx. 24–48 V battery system | Exact pack size depends on drive motors and control electronics |
Drawings
All dimensions below are approximate planning values. The drawings are measured concept views, not fabrication drawings.
3D concept model
This JSON block describes a simple massing model in the same planning units as the drawings.
How it works
- The battery pack supplies power to the drive motors, lights, and control electronics.
- The controller receives route commands and sensor feedback, then adjusts speed and steering to keep the robot on course.
- The cargo bay keeps drinks and food separate from the wheelbase, with a low center of gravity to help stability.
- At stops, the robot waits until a person loads or unloads the order, then continues along the route at low speed.
- Weather protection should be planned around electronics, wheel splash, and any food temperature requirements.
Parts and materials
| # | Part | Typical spec | Qty | Est. unit price | Est. total | Supplier type |
|---|---|---|---|---|---|---|
| 1 | Frame base | Welded or bolted aluminum frame, approx. 30 × 24 in | 1 | $350–$900 | $350–$900 | Metal fabricator / extrusion supplier |
| 2 | Cargo enclosure | Light panel shell with weather-resistant finish | 1 | $250–$700 | $250–$700 | Fabrication shop / enclosure supplier |
| 3 | Roof module | Protective top cover with sealed edges | 1 | $120–$350 | $120–$350 | Fabricator / plastics supplier |
| 4 | Front bumper | Energy-absorbing trim or polymer bumper | 1 | $40–$120 | $40–$120 | Industrial parts supplier |
| 5 | Rear bumper | Matching rear protection piece | 1 | $40–$120 | $40–$120 | Industrial parts supplier |
| 6 | Drive wheel set | Rubber tire wheel assembly with bearings | 2 | $80–$220 | $160–$440 | Mobility parts supplier |
| 7 | Rear wheel set | Matching wheel assembly or support caster | 2 | $80–$220 | $160–$440 | Mobility parts supplier |
| 8 | Motor and gearbox | Low-speed electric drive unit, sized by load | 2 | $250–$700 | $500–$1,400 | Electric drive supplier |
| 9 | Battery pack | Approx. 24–48 V lithium battery system | 1 | $450–$1,200 | $450–$1,200 | Battery supplier / integrator |
| 10 | Battery management and charger | Matched charger, BMS, and safety disconnects | 1 | $250–$700 | $250–$700 | Power electronics supplier |
| 11 | Controller, sensors, and wiring | Motion controller, obstacle sensing, cabling, switches | 1 | $900–$2,000 | $900–$2,000 | Automation / robotics supplier |
| 12 | Lighting and visibility kit | Front, rear, and side lighting with reflectors | 1 | $80–$250 | $80–$250 | Vehicle safety supplier |
| 13 | Fasteners, hinges, seals | Stainless hardware, weather seals, service latches | 1 lot | $120–$350 | $120–$350 | Hardware supplier |
Rough total budget: approx. $3,380–$7,970
Typical retail estimates only. Prices can move a lot depending on sourcing, control system complexity, and whether the frame is custom fabricated.
Build phases
1. Define route and payload
1–2 weeks. Confirm sidewalks, stops, slope, weather, and delivery use cases.
1–2 weeks. Confirm sidewalks, stops, slope, weather, and delivery use cases.
2. Mechanical concept
2–4 weeks. Frame, wheelbase, enclosure, access points, and serviceability.
2–4 weeks. Frame, wheelbase, enclosure, access points, and serviceability.
3. Electrical and control layout
2–5 weeks. Battery, motor controller, sensors, wiring, and safety shutoff.
2–5 weeks. Battery, motor controller, sensors, wiring, and safety shutoff.
4. Prototype fabrication
3–6 weeks. Build the first body, mount components, and test rolling behavior.
3–6 weeks. Build the first body, mount components, and test rolling behavior.
5. Software and tuning
3–8 weeks. Navigation logic, stop behavior, obstacle detection, and speed limits.
3–8 weeks. Navigation logic, stop behavior, obstacle detection, and speed limits.
6. Safety review and pilot
2–6 weeks. Professional review, limited campus pilot, and rule checks.
2–6 weeks. Professional review, limited campus pilot, and rule checks.
Safety, rules and permits to check
- Campus or city sidewalk operating rules, including where low-speed robots are allowed.
- Local transportation or public works rules for shared pedestrian space and curb crossings.
- Electrical safety and battery handling rules for charging, storage, and maintenance.
- Fire code guidance if the battery, charger, or storage area is indoors.
- Accessibility and pedestrian safety requirements so the robot does not block walkways.
- Insurance and liability review for property damage, injury, and operating permissions.
Rules depend on the country and state. The exact authority may be a city transportation office, campus risk management office, fire marshal, building department, or state-level regulator.
Who to involve
- Mechanical engineer — checks frame strength, wheel loading, enclosure mounting, and service access.
- Electrical engineer — checks battery sizing, charging, wiring protection, and shutdown safety.
- Robotics or control engineer — checks sensors, motion logic, low-speed control, and fail-safe behavior.
- Industrial designer — checks shape, visibility, user interaction, and ease of loading.
- Safety or compliance consultant — checks local rules, warnings, operating procedures, and liability concerns.
Open questions to decide next
- Should the robot carry drinks only, or both drinks and food?
- Do you want one cargo bay or separate hot and cold compartments?
- Should it be built for indoor charging only, or dock outside as well?
- Would you prefer a simpler manual-assist version first, or a fully autonomous pilot?
- What are the exact route slopes, curb heights, and door thresholds on campus?