1.5. System architectures

In this section, we will explore the development of the physical architecture for the package delivery UAV system. We will start with some guidelines for designing the physical architecture of a system that enables us to evaluate and eliminate unsuitable concepts.

1.5.1. Guidelines for Developing System Architectures

Designing the physical architecture of a system involves several systematic steps to ensure that the final design meets all system requirements and operational needs. The following methodology outlines these steps and includes criteria to eliminate unsuitable concepts.

1. Define Physical Requirements

   • Extract from System Requirements: Identify all physical constraints and requirements from the system specifications

   • Consider Environmental Factors: Include factors such as operating environment, takeoff and landing constraints, and maneuverability

   • Regulatory Compliance: Ensure adherence to relevant standards and regulations

2. Identify Candidate Architectures

   • List Possible Architectures: Enumerate all feasible physical architectures

   • Consider Technology Readiness: Evaluate the maturity of technologies required for each architecture

3. Establish Evaluation Criteria

   • Operational Suitability: Assess how well each architecture meets the mission profile

   • Performance Metrics: Include payload capacity, range, speed, endurance, and maneuverability

   • Environmental Compatibility: Consider noise levels, emissions, and impact on surroundings

   • Constraints Compliance: Evaluate how each architecture aligns with physical, regulatory, and operational constraints

4. Perform Trade-Off Analysis

   • Quantitative Assessment: Use scoring or weighting methods to compare architectures against criteria

   • Qualitative Assessment: Consider factors like complexity, maintainability, and scalability

5. Eliminate Unsuitable Concepts

   • Threshold Criteria: Set minimum acceptable levels for critical requirements

   • Feasibility Assessment: Discard architectures that do not meet essential requirements or pose significant challenges

6. Select Best Architecture (Qualitatively)

   • Align with Requirements: Choose the design that best meets the system requirements and mission profile

   • Validate Feasibility: Ensure that the selected architecture is practical, manufacturable, and maintainable

1.6. Example: System Architecture Selection for Lifting and Handling UAV

1.6.1. Step 1: Define Physical Requirements

1.6.1.1. Extract from System Requirements

• Payload capacity: 25–100 kg.

• Operational range: Up to 5 km in urban environments.

• Flight duration: 30 minutes minimum per mission.

• Height: 24 m (maximum)

1.6.1.2. Consider Environmental Factors

• Operating environment: Constrained urban areas with rooftop landings.

• Weather tolerance: Winds up to 20 km/h, light rain resistance.

• Maneuverability: High agility for takeoff and landing in limited spaces.

1.6.1.3. Regulatory Compliance

• Adherence to local aviation regulations (e.g., FAA, EASA).

• Restricted airspace compliance and noise level restrictions.

1.6.2. Step 2: Identify Candidate Architectures

1.6.2.1. List Possible Architectures

1. Fixed-Wing UAV: Long endurance but limited in vertical takeoff/landing.

2. Multirotor UAV: Highly agile with vertical takeoff/landing capabilities.

3. Hybrid VTOL UAV: Combines fixed-wing and multirotor capabilities.

1.6.2.2. Consider Technology Readiness

• Fixed-Wing: High readiness but limited for constrained spaces.

• Multirotor: Proven technology for payload lifting in tight environments.

• Hybrid VTOL: Emerging technology; readiness depends on payload size.

1.6.2.3. Energy source

Fig. 1.5 Conventional multirotor UAV.

Fig. 1.6 Multirotor UAV with cable.

1.6.3. Step 3: Establish Evaluation Criteria

1.6.3.1. Operational Suitability

• How well does the architecture fit urban delivery scenarios?

1.6.3.2. Performance Metrics

• Payload capacity: Support 25–100 kg

• Endurance: At least 30 minutes per mission

• Speed: 10–20 km/h for safe urban navigation

1.6.3.3. Environmental Compatibility

• Emissions: Low-carbon electric propulsion preferred

• Noise: Should be compatible with noise levels of construction sites

1.6.3.4. Constraints Compliance

• Meet regulatory standards for urban UAV operations

1.6.4. Step 4: Perform Trade-Off Analysis

1.6.4.1. Quantitative Assessment

Architecture	Payload Capacity	Range	Maneuverability	Noise	Technology Readiness
Fixed-Wing	Moderate	High	Low	Low	High
Multirotor	High	Moderate	High	High	High
Hybrid VTOL	High	High	Moderate	High	Moderate

1.6.4.2. Qualitative Assessment

• Fixed-Wing: Complex in urban environments, poor maneuverability.

• Multirotor: High agility, simple maintenance, ideal for constrained areas.

• Hybrid VTOL: Promising but may introduce complexity and higher costs.

1.6.5. Step 5: Eliminate Unsuitable Concepts

1.6.5.1. Threshold Criteria

• Must support 25–100 kg payloads.

• Must allow vertical takeoff/landing.

1.6.5.2. Feasibility Assessment

• Fixed-Wing: Eliminated due to poor maneuverability in constrained spaces.

• Hybrid VTOL: Promising but less practical given cost and readiness.

1.6.6. Step 6: Select Best Architecture (Qualitatively)

1.6.6.1. Selected Architecture

• Multirotor UAV: Selected for its high agility, proven technology, and suitability for constrained environments.

• The question of cable or not cable shall be evaluated.

1.6.6.2. Validation Feasibility

• Practical, manufacturable, and maintainable with current technology.

• Meets all operational and regulatory requirements.

1.7. Quiz

Test yourself with this quiz.