What Exoskeletons Do Firefighters Use for Search and Rescue Operations?

I. Overview

In recent years, the application of exoskeleton technology in the firefighting field has gradually moved from the laboratory to real-world scenarios, especially in high-frequency, high-load scenarios such as high-rise fire search and rescue, heavy object handling, and long-term operations. It has become an important piece of equipment for alleviating the physical stress on firefighters and improving operational safety, but it is still in the early stages of large-scale application. To achieve large-scale promotion and use of firefighting exoskeletons, three fundamental requirements need to be met: 1. Ensuring the safety of firefighters during operations; 2. Effectively reducing the physical exertion of firefighters; 3. Adapting to high-frequency operational scenarios such as climbing stairs.

The key to achieving these three requirements lies in "lightweight + active + long battery life": lightweight design prevents the equipment from becoming an additional burden, active assistance directly affects climbing and load-bearing efficiency, and long battery life ensures continuous operational capability. Special note: Currently, firefighting exoskeleton equipment cannot directly withstand high-temperature environments. It must be used in conjunction with professional heat-resistant clothing, and the duration of each operation must be controlled according to the ambient temperature to avoid damage to the electronic components of the equipment and affecting operational effectiveness.

Principle The core: logic behind firefighter exoskeletons reducing physical exertion and increasing load capacity for firefighters is to use mechanical assistance to distribute muscle load, thereby reducing the body's energy metabolism needs and ultimately reducing physical exertion. This is achieved through two main mechanisms: reducing muscle load and decreasing metabolism.

Precise Distribution of Muscle Load via Mechanical Assistance: The exoskeleton is driven by dual-joint motors at the hip and knee joints, combining leverage and torque compensation technology to provide targeted assistance during key gait cycles when climbing stairs. For example, when lifting the leg to climb stairs, the hip joint motor outputs thrust to distribute more than 50% of the load on the quadriceps femoris muscle on the front of the thigh, while the knee joint motor provides supporting torque during the support phase, reducing the need for the calf muscles and hamstrings to exert force. Simultaneously, the device is equipped with 10+ IMU inertial sensors and pressure sensors to perceive changes in the firefighter's gait, speed, and load in real time, adjusting the assistance level within 0.03 seconds to achieve a synchronized response of "assistance starts when the person moves and stops when the person stops," avoiding

the extra energy expenditure caused by delayed or excessive assistance. Laboratory data shows that when firefighters wear exoskeletons to climb stairs, the activation level of their lower limb core muscles decreases by 36%-48%, and muscle fatigue decreases by more than 40%.

Optimization of Physiological Metabolic Pathways: The reduction in muscle load directly lowers the oxygen uptake requirement of firefighters. When climbing stairs, the body needs to increase breathing and blood circulation to provide energy for the muscles. After the exoskeleton takes on about 50% of the muscle work, oxygen uptake can be reduced by 20%-35%, significantly reducing cardiovascular system pressure and lowering heart rate by 15%-25% compared to the unequipped state (for example, based on actual data of a firefighter weighing 75kg climbing 10 floors, his peak heart rate decreased from 168 beats/minute to 143 beats/minute). At the same time, the reduction in energy consumption allows firefighters to climb more than 30% higher and extend the duration of their work by 40% with the same physical reserves, effectively alleviating fatigue accumulation after high-intensity work and reducing safety risks caused by physical exhaustion.

Functional Analysis: Firefighters need to maneuver flexibly and carry heavy loads in diverse terrains such as flat ground and stairs for search and rescue operations. Firefighting exoskeletons, with their core functions including powerful power assistance, load sharing, human motion adaptation, and multi-terrain recognition, precisely match the requirements of operational scenarios and are highly adaptable to the practical needs of firefighters climbing buildings for search and rescue.

Power Assistance: Strong Torque Ensures Climbing Efficiency

* Key Indicators: Maximum torque of dual joints ≥ 25 N·m, assistance ratio in climbing scenarios ≥ 40%, supports adaptive climbing speed of 0.5-2 m/s.

* Scenario Significance: When firefighters wear fire suits and carry air respirators (approximately 15 kg) and rescue equipment (approximately 10 kg), the torque required for climbing buildings is more than three times that of walking on flat ground. A torque output of over 25 N·m ensures easy climbing of buildings with a load of 30 kg or more; the 40% assistance ratio directly increases climbing efficiency.

The building's energy consumption is reduced to 60% of that without equipment, avoiding the "getting more tired as you climb" effect caused by insufficient torque, and ensuring firefighters' judgment and operational flexibility during search and rescue operations.

 Load-Bearing Function: Shoulder Load Reduction Focuses on Core Operations

* Key Indicators: Shoulder load-bearing ratio ≥60%, maximum load capacity ≥35kg, compatible with commonly used equipment such as fire-fighting air respirators and rescue ropes.

* Significance in Scenarios: Firefighters typically carry loads of 25-40kg during routine operations. Long-term shoulder loads can easily lead to neck and shoulder strain, excessive pressure on the lumbar spine, and even affect upper limb operational flexibility. The exoskeleton, through a rigid frame and intelligent sling structure, directly transfers over 60% of the load to the ground, reducing the actual shoulder load to less than 10kg; simultaneously, the distributed load design reduces center of gravity swaying during walking and climbing, lowering the risk of falls due to load imbalance, allowing firefighters to focus more on search and rescue route planning and the transfer of trapped personnel.

Flexibility and Speed: Rapid Response and Search and Rescue Efficiency

Core Indicators: Climbing speed ≥ 1.2 m/s (with a 25 kg load), joint range of motion adapted to the natural human gait (hip flexion/extension 0-120°, knee flexion/extension 0-150°), turning response time ≤ 0.5 seconds.

Scenario Significance: In high-rise fire search and rescue, the "golden rescue time" is crucial. A climbing speed of 1.2 m/s allows firefighters to reach a 10-story building within 1 minute (based on a floor height of 3 m), saving more than 30% of time compared to unequipped conditions. The joint range of motion conforms to the natural human gait, ensuring smooth movements such as climbing, turning, and bending, avoiding equipment limitations that could hinder search and rescue operations, especially allowing for flexible posture adjustments in narrow stairwells and corridors.

Staircase Terrain Recognition: Intelligent Adaptation to Complex Environments

* Key Indicators: Equipped with a camera + area-array dTOF visual recognition system, staircase terrain recognition response time ≤30ms, supports adaptive staircase slope within 30°, and can distinguish common types such as straight staircases and turning staircases.

* Significance in Scenarios: Stairwells at fire scenes may have problems such as smoke obstruction and dim lighting. The visual recognition system, integrated with an AI motion engine, can predict staircase terrain in advance and automatically adjust joint assist torque and support angle—for example, increasing the hip joint assist ratio when facing steep staircases and optimizing the center of gravity transfer trajectory when facing turning staircases, avoiding misjudging terrain and causing tripping or imbalance, thus improving operational safety in complex staircase environments.

 Lightweight Design: Burden-Free Operation

* Core Threshold: Total equipment weight ≤ 3kg; main body material adopts carbon fiber + aerospace aluminum alloy composite structure; donning time ≤ 5 minutes.

* Scenario Significance: Firefighters already bear a significant load while wearing fire suits and breathing apparatus. A lightweight design of less than 3kg ensures the exoskeleton will not become an "extra burden," and even achieves a "heavy yet lighter" experience with assistance. The carbon fiber and aerospace aluminum alloy materials combine high strength and impact resistance, withstanding minor collisions during rescue operations. The 5-minute quick donning design adapts to the emergency deployment needs at fire scenes, ensuring timely rescue.

IV. Selection Comparison: Active Exoskeleton vs. Passive Exoskeleton

In summary, powered exoskeletons, with their precise power assistance, flexible human movement adaptation, and stable battery life, are better positioned to meet the core needs of firefighters in building climbing and search and rescue scenarios, requiring reduced load, mobility, and continuous operation. Among them, Kenqing Technology's Ant®-P1 and π series powered exoskeletons are specifically tailored to the different needs of firefighting operations: the Ant®-P1, as a professional-grade assistive device, weighs only 3.7kg, boasts 28Nm of power, and a maximum speed of 15km/h. It is equipped with a professional detachable load-bearing back frame, effectively distributing the pressure of carrying rescue supplies and significantly reducing physical exertion during building climbing. While the π and π6 series lack a dedicated load-bearing structure, their ultra-lightweight design (π only 1.8kg, π plus 2.1kg) achieves exceptional mobility, while also possessing precise terrain recognition capabilities and extended battery life, making them more adaptable and perfectly suited to the rapid building climbing and flexible search and rescue requirements of firefighters in light-load scenarios.