Parcours

Highly repetitive tasks, extern weights, and non-ergonomic postures are typical for workplaces in intralogistics and are considered as being particularly stressful for the human body, especially the lower back.

This Parcour depicts a realistic, representative task of a “band-cleaner” in an automotive plant.
8 kg packages, each marked with one of two colors, have to be picked from a table (representing a belt) and carried to one of two grid boxes 2 m away. The packages are sorted according to their markings into the grid boxes. For the transport of one package, the time is limited to 10-seconds, which is based on the rhythm in logistics of the automotive industry. A running info clock gives a rough time for sorting each package so that all 48 packages are sorted within 8-minutes. After one sorting round, the test subject has a 2-minute break during which a questionnaire is filled out related to their subjective effort and body discomfort during the work.

After the break, the test subject has to sort the packages back to the table. This process of placing 48 packages in grid boxes within 8-minutes and back to the table in the next round is repeated three times so that the total working time is 1-hour. After working for 1-hour with an exoskeleton, the subjects fill out a questionnaire about the wearing comfort and the usability of this system. After at least a 2-hour break the subject would repeat the task with or without exoskeleton (randomized).

There is repetitive overhead work in car assembly and maintenance at car service garages. These tasks can cause work-related musculoskeletal disorders in the shoulders, neck, and upper extremities and, likewise, affect the precision of the work due to muscle fatigue.

Therefore, in this Parcour, tasks of an underbody assembly in an automotive plant are simulated as realistic working processes in an automotive plant. This includes assembly and disassembly tasks (for experimental practicality) 

•     setting clips (12 clips)
•     screwing with a battery screwdriver (16 screws)
•     laying cables into nine cable holders (2 cables)
•     painting lines (25 times, lines of 390 mm each)

Each individual task is performed in a given time according to the “Method-Time-Measurements” (MTM), which is common in the automotive industry internationally. Thus, time is to be respected, as well as accuracy, especially in painting lines. One working round consists of assembly and disassembly followed by a 2-minute break. After each round, the subjects complete a questionnaire about subjective effort and body discomfort during work. A total of seven rounds are completed in 1-hour. After completing the Parcour with an exoskeleton, the individual wearing comfort is assessed after the 1-hour work. A System Usability Scale (SUS) score is used related to the usability of the exoskeleton.

Between the two conditions with and without an exoskeleton, the subjects have at least a 2-hour break.

Highly repetitive tasks, extern and unhandy weights as well as non-ergonomic postures are typical for workplaces in intralogistics and are considered as being particularly stressful for the human body, especially the lower back.

8 kg bags, each marked with one of two colors, must be picked up from a table, which represents a belt or shelf, and carried over a distance of 2 m to one of two grid boxes. The bags are stacked in one of the two grid boxes according to their two different color markings. A running clock gives the subjects a rough schedule to keep to clear 48 bags within 8-minutes. After 8-minutes, the subject has a short break of 2-minutes during which a questionnaire is filled out related to their subjective effort and body discomfort during the work. Then the subject sorts the sacks back onto the table. The process of transporting the bags into the grid boxes and back onto the belt is repeated three times so that the subject works for one hour.

After working 1-hour with an exoskeleton, the subjects fill in a questionnaire about the user feedback on and the usability of this system. After at least a 2-hour break the subject would repeat the task with or without an exoskeleton (randomized).

Construction activities are considered to pose an extreme strain on the whole body due to physically demanding tasks. In particular, laying pipes or cable trays on walls and ceilings puts exceptional strain on the shoulders.

This Parcour represents an overhead installation routine of a two-part L-shaped system. The first task is a simulated drilling process by applying a defined force into a sensory drill hole using a shut-off power drill at eye-level and overhead. The subject receives visual feedback on the applied force and duration. Then the rail system is installed by first, mounting a cantilever to the wall, second, screwing a saddle flange to the ceiling, third, mounting a rail to it, and last, connecting rail and cantilever. The process, comprising drilling and installation, is performed on both the left and right sides. Eventually, rail systems are disassembled again.

One working round consists of simulated drilling, installing, and disassembling followed by a 2-minutes break. After each round, the subject fills in a questionnaire related to subjective effort and body discomfort during work. Four rounds are completed within one hour. After completing the 1-hour Parcour with an exoskeleton, the individual user's comfort is assessed. Additionally, a score of the System Usability Scale (SUS) is used to inquire about the user’s acceptance of the exoskeleton.

Activities in an overhead position are particularly stressful for the upper extremities and frequently cause musculoskeletal complaints.  For example, this kind of overhead work is well known in drywall construction when working with drywalls.

This Parcour represents a drywall construction and is divided into two tasks: screwing and sanding.

One round of work consists of screwing 36 screws and grinding on the wall and ceiling, followed by a 2-minute break. After each round, the subject completes a questionnaire on subjective effort and body discomfort during work. Six rounds are completed within one hour; the first and last rounds are performed with a cordless drywall screwdriver and the rounds between with a dummy.

After completing 1-hour with an exoskeleton, the user's comfort is assessed. A System Usability Scale (SUS) score is also used to inquire about the user’s acceptance of the exoskeleton. After at least a two-hour break, the subject would repeat the task with or without an exoskeleton.

This Parcour is developed in Excellence Cluster IntCDC and was defined in cooperation with SchwörerHaus KG, where overhead lifting activities of heavy timber beams and repetitive demanding tasks of overhead positioning are common. Two people are working simultaneously and synchronized in the same workplace.

In cooperation with technician students from the vocational school Wilhelm-Maybach-Schule Bad Cannstatt, a workplace of changing tires was defined and developed.

In agriculture, it is common to work in the field to plant and pick fruits, vegetables, or seeds and then carry them in boxes.   

The task of picking, placing in a field, and carrying boxes are demonstrated here.

Subjective user feedback is assessed using a questionnaire. After each trial, the physical strain of the activity as well as the strain on the individual body parts is recorded. At the end of the activity with an exoskeleton, the usability of the exoskeleton (SUS scale) is also surveyed.

The quality score is task-specific and therefore Parcour-specific.

Parcour Car Assembly: Duration of the activity (working time) and the Accuracy in task (pixel overpainting the specified line).

Parcour Welding: Weldseam quality by an AR simulator.

Parcour Drywall: Precision of whether a screw is countersunk is measured in comparison without preload (trial 1) to with preload (trial 6).

In sEMG, electrodes are used to measure the naturally occurring electrical voltage in the muscle. The measured voltages are normalized to a maximum voluntary contraction (MVC) and then an average value [%MVC] is formed over defined periods. Depending on the activity, the main muscle to be relieved is recorded in combination with the movement. The M. erector spinae is recorded for forward bending tasks and the M. deltoideus anterior and medial for shoulder flexion tasks.

The dynamic cardiac output can be determined by the non-invasive impedance cardiography. It is based on the variation of the electrical thoracic impedance. From the signals derived from the ECG (electrocardiogram), the ICG (impedance cardiograph), and the PW (pulse wave), the signal-processing software of this measuring system, which is approved as a medical device, determines hemodynamic parameters to determine the performance physiology.