Human-Robot Collaboration: Designing Cobot Workspaces Around the Human Body

Collaborative robots have moved from trade show demonstrations to everyday production. They hand parts to operators, hold workpieces during assembly, drive screws while a person positions a component and take over the repetitive lifting that places demands on the shoulders and back. The promise is a workstation where people and robots each do what they do best.

That promise depends on a detail that is easy to underestimate: the collaborative application must be designed around the people doing the work. Where the robot meets the operator, at what height, at what speed and with what contact forces, determines whether the cell improves ergonomics or simply relocates the strain. Collaborative robotics is, at its core, a human factors problem.

Avoiding Collisions Is Not the Same as Fitting the Operator

Cobot projects tend to focus first on safety, and rightly so. ISO 10218-1 and ISO 10218-2, both revised in 2025, set safety requirements for industrial robots and robot applications. The 2025 revision of Part 2 brings in the collaborative-application guidance first published in ISO/TS 15066, including limits on force and pressure for contact with different body regions.

Managing collision risk does not, by itself, resolve awkward reaches, sustained shoulder elevation or repetitive trunk bending. A robot that presents parts at a fixed height may force short operators to reach up and tall operators to stoop. A shared workspace that is safe from collision may still require awkward twisting to avoid the robot’s path. These demands need to be evaluated across the full work cycle.

Where Human Body Data Enters Collaborative Cell Design

Design decision	Relevant human data	Why it matters
Handover location	Standing elbow height, reach envelope, shoulder range of motion	Parts handed over at the wrong height or distance push the operator into awkward posture
Shared workspace layout	Body volume during movement, typical work postures	Identifies where operator movements overlap the robot’s operating envelope and where further risk assessment is needed
Contact assessment	Body region location and size	Helps designers identify foreseeable contact locations across operators of different sizes
Speed and separation	Walking and arm movement speed, approach direction	Human approach assumptions must be considered alongside sensing uncertainty, system response time and robot stopping performance
Visibility and cues	Eye height and visual field	The operator should be able to see the robot’s status and understand its next movement from their normal working position

Designing the Handover

In tasks involving part exchange, the handover is a critical ergonomic interface. A robot that always presents parts at the same coordinates treats every operator as identical. In a workforce that spans a wide range of statures, this can leave some operators reaching too high or too far, while others bend forward for every cycle.

Good handover design follows the same principles as good workstation design: keep the exchange close to the body, near elbow height and within the comfortable reach zone. Elbow height is a useful starting point, but the handover position also depends on part weight, grip orientation and the next step in the task. Because robots are programmable, they offer an additional way to adapt the workstation to individual operators. The handover point can be adjusted to the operator, either through configured profiles or by sensing operator position and posture.

Shared Workspace and the Space People Actually Occupy

Static anthropometric dimensions describe the body in specified measurement postures. Real operators move: they shift their weight, step to the side, reach across the bench and turn to pick up tools. The volume a person occupies during a work cycle is considerably larger than their static body envelope.

Capturing this dynamic occupied space, through motion data or simulation with digital humans, is essential for collaborative layout. It helps identify overlaps between human and robot motion, compare layout options and locate situations that require closer safety assessment. The resulting layout still needs application-specific verification and validation. It also reveals where the operator must contort to stay out of the robot’s way, which is an ergonomic warning sign. For a broader look at why robotics is turning to human motion, see Why Robots Are Learning from Human Joint and Motion Data.

Contact Limits and Body Region Mapping

For power and force limited applications, the collaborative-application guidance first published in ISO/TS 15066, and reflected in the 2025 revision of ISO 10218-2, sets biomechanical limits by body region. Applying those limits requires knowing which body regions are likely to be in the robot’s path, at what heights, for operators of different sizes. The body region exposed to a potential contact can change with operator stature, posture and task phase.

3D human body data allows teams to map body regions within the shared workspace for a representative range of operators, rather than assuming a single operator. This mapping helps teams identify foreseeable contact scenarios for application-specific risk assessment and subsequent verification of protective measures.

Simulating Collaborative Cells with Digital Humans

Because collaborative cells combine human motion, robot motion and shared space, simulation is particularly valuable. A practical approach combines robot simulation with digital human models:

1. Define the operator population. Select representative 3D operator models covering the stature and body shape range of the workforce.
2. Simulate the task sequence. Model the operator’s movements and the robot’s path through a full cycle.
3. Evaluate posture. Score reach, trunk bending and shoulder elevation at each step, particularly at handover.
4. Check proximity and contact. Identify where and with which body regions the operator and robot come closest.
5. Iterate. Adjust handover points, robot paths and fixture locations and re-run the evaluation.

Research on applying digital humans in design is developing alongside these tools. In a study first-authored by Comfo Labs CEO Wonsup Lee, Lee, Jung and You (2024) examined the applicability of parameterized digital humans in anthropometric and ergonomic product design studies.

Through SIZE LAB, Comfo Labs provides 3D body-shape data, anthropometric measurements and representative 3D personas to help teams define the operator population for ergonomic evaluation.

Integrating Cobots into Existing Workstations

Many collaborative robots are not installed in new purpose-built cells but retrofitted into existing workstations. That creates specific ergonomic risks. The robot takes over part of the task, but the remaining human tasks are often left where they were, even when the robot’s footprint changes the operator’s access and posture.

Common issues in retrofit projects include:

• Displaced reach. The robot occupies the space where parts or tools used to sit, pushing them to the edge of the operator’s reach.
• New sight-line obstructions. The robot arm blocks the operator’s view of the workpiece or of status indicators.
• Changed working height. Fixtures raised or relocated to suit the robot no longer suit the operator.
• Pacing effects. The robot sets a fixed cycle time that removes the natural variation operators used to recover between demanding steps.

Treating the retrofit as a redesign of the whole workstation, rather than the addition of a machine, helps identify and address these problems. Re-evaluating the operator’s tasks with representative body models after the robot is placed in the layout is a useful design check.

Collaborative Robot Ergonomics Checklist

• Handover position: Does the exchange point suit operator size, part weight, grip orientation and the next task?
• Reach: Can all operators take and return parts without full arm extension?
• Adaptability: Can the robot adjust handover location to individual operators?
• Occupied space: Has the operator’s dynamic working volume been mapped, not just the static body?
• Body regions: Are contact risk assessments based on body region locations for operators of different sizes?
• Posture under avoidance: Do operators need to twist or lean to stay clear of the robot path?
• Visibility: Can operators see robot status and intent from their working position?

A well-designed collaborative cell accounts for the operator’s reach, posture and movement alongside the robot’s capabilities. Those requirements should shape the layout from the start.

Frequently Asked Questions

References

• Gualtieri, L., Rauch, E., & Vidoni, R. (2021). Emerging research fields in safety and ergonomics in industrial collaborative robotics: A systematic literature review. Robotics and Computer-Integrated Manufacturing, 67, 101998. https://doi.org/10.1016/j.rcim.2020.101998
• International Organization for Standardization. (2025). ISO 10218-1:2025: Robotics — Safety requirements — Part 1: Industrial robots. https://www.iso.org/standard/73933.html
• International Organization for Standardization. (2025). ISO 10218-2:2025: Robotics — Safety requirements — Part 2: Industrial robot applications and robot cells. https://www.iso.org/standard/73934.html
• International Organization for Standardization. (2016). ISO/TS 15066: Robots and robotic devices — Collaborative robots. https://www.iso.org/standard/62996.html
• Lee, W., Jung, H., & You, H. (2024). Applicability of parameterized digital humans in anthropometric and ergonomic product design studies. In Proceedings of the 22nd Triennial Congress of the International Ergonomics Association (IEA 2024), Jeju, Korea. https://handonghci.github.io/WonsupLee/publication.html