Gait trajectory‐based interactive controller for lower limb exoskeletons for construction workers

Abstract

Lower limb exoskeletons (LLEs) are sets of mechanical devices used to support the action of human lower limbs. This recently developed technology has unprecedented potential in the construction industry by increasing the strength, endurance, and other physical capabilities of construction workers. For safety considerations, LLEs need reliable and responsive controllers to closely match their mechanical operation with human gait in a synchronous manner. This research proposes the use of physical human–robot interactive (pHRI) controllers that are suitable for construction tasks. The proposed pHRI integrates a gait trajectory‐based musculoskeletal model with iterative control algorithms. To minimize the trajectory tracking error between LLEs and human lower limbs, the gait dynamic was modeled as a spring damping and impedance model for supporting and swing phases. An iterative adaptive controller was developed for trajectory tracking and predication. To validate the proposed model, an in‐lab experiment to simulate typical construction activities was conducted, allowing us to assess tracking error. The experiment results suggest that the proposed model can minimize the trajectory tracking error to a level acceptable for safe operation. The iterative controllers allow fast error convergence for different construction scenarios with proper calibration. Therefore, the proposed pHRI iterative controllers are reliable and suitable for complicated activities within the dynamic working conditions intrinsic to construction sites.

Intelligent robots and human–robot collaboration in the construction industry: A review

“…In recent years, many exoskeleton prototypes have been developed to experiment or verify their application in various industries, such as SPEXOR [102], hybrid assisted limb [103], and Berkeley Lower Extremity Exoskeleton [104]. For the application in the construction industry, Yu et al [105] developed an upper-limb exoskeleton robot for steel manufacturing. Robots have been adopted in helping refractory construction operations in furnaces.…”

Evaluating the drivers for the implementation of automation techniques in the Nigerian construction sector

“…, 2019). Exoskeletons are often described as exosuits, wearable robots or supersuits, which are wearable machines with motorized joints that are designed to provide support, disperse weight and correct posture to minimize the risk of strain as well as injuries on construction sites (Ren et al. , 2022).…”

“…Exoskeletons are described as mechanical devices that are worn by construction workers to augment and boost human performance (Delgado et al, 2019). Exoskeletons are often described as exosuits, wearable robots or supersuits, which are wearable machines with motorized joints that are designed to provide support, disperse weight and correct posture to minimize the risk of strain as well as injuries on construction sites (Ren et al, 2022). Exoskeletons also enable construction workers to move faster and in some cases can turn a user into a "super worker" who can lift heavy loads with greater endurance.…”

Real‐time ergonomic risk assessment in construction using a co‐learning‐powered 3D human pose estimation model

“…With the maturity of wearable technology (B. Ren et al, 2022;Yoong et al, 2019), wearable sensing, especially initial measurement units (IMUs), is a promising alternative for precisely capturing human postures (Chen et al, 2017;D. Wang et al, 2015).…”

“…The committed step is to accurately estimate workers’ postures. With the maturity of wearable technology (B. Ren et al., 2022; Yoong et al., 2019), wearable sensing, especially initial measurement units (IMUs), is a promising alternative for precisely capturing human postures (Chen et al., 2017; D. Wang et al., 2015). Yan, Li, Li, & Zhang, 2017) proposed a real‐time motion capturing and warning system based on wearable IMUs that enable workers to be aware of ergonomic risks and make adjustments for the prevention of WMSDs.…”