What Makes a Robot “Collaborative”?
Motionwell integrates collaborative robots from Universal Robots, JAKA, and other platforms across medical device, electronics, and manufacturing facilities in Singapore. From that experience, one point is clear: “collaborative robot” describes a robot designed for use around people, but safe collaboration is achieved by system design, not by the robot alone.
| Topic | What it means in practice |
|---|---|
| Cobot as a product | The robot has built-in safety functions and a design intended for human proximity |
| Collaboration as an application | The workcell is engineered so that the risk level is acceptable for the intended task |
ISO/TS 15066 is the reference that helps you engineer the second part: the application.
Standards You Actually Use (And What Each Covers)
| Standard | Scope | Why it matters |
|---|---|---|
| ISO 10218-1 / ISO 10218-2 | Industrial robot safety (robot and integration) | Baseline safety expectations for industrial robot systems |
| ISO/TS 15066 | Collaborative operation guidance | Defines collaboration modes and provides guidance for risk reduction |
| ISO 12100 | Risk assessment methodology | How to systematically identify and mitigate hazards |
| ISO 13849 (or IEC 62061) | Functional safety design | How to implement safety functions to required performance levels |
Four Collaboration Modes (ISO/TS 15066)
ISO/TS 15066 describes four commonly used ways to achieve safe collaboration. The “best” mode depends on the task, tooling, and exposure.
| Collaboration mode | What happens | Typical fit | Typical safety functions |
|---|---|---|---|
| Safety-rated monitored stop | Robot stops when a person enters the collaborative space | Occasional human intervention | Safety-rated sensors, stop and reset logic |
| Hand guiding | Operator guides robot motion directly | Teaching, setup, ergonomic assist | Enable device, reduced speed mode, accessible e-stop |
| Speed and separation monitoring | Robot slows/stops based on distance to a person | Shared area with predictable traffic | Safety scanners, zoning, dynamic speed limits |
| Power and force limiting (PFL) | Robot limits impact energy in contact scenarios | Close interaction tasks | Force/torque limits, speed limits, validated tooling design |
ISO/TS 15066 also provides guidance on body-region-specific transient contact thresholds and measurement methods. Always consult the latest revision and validate your specific end-effector and workpiece risks.
Risk Assessment Workflow (Engineering View)
| Step | Output you should expect |
|---|---|
| Identify hazards | A hazard list that includes tooling, workpieces, pinch points, and unexpected motion |
| Estimate risk | Severity and probability assumptions documented (not “in someone’s head”) |
| Select safeguards | Engineering controls prioritized before administrative controls |
| Implement safety functions | Safety I/O map, safety PLC or safety relay logic, verified stop behavior |
| Validate and document | Test records, measured limits where required, and sign-off evidence |
Typical Safety Functions in a Cobot Cell
| Safety area | Typical implementation patterns |
|---|---|
| Zone awareness | Safety scanners or interlocked doors defining speed-limited and stop zones |
| Stop architecture | System-level e-stop network, controlled stop categories, safe restart rules |
| Tooling and workpiece safety | Rounded edges, limited protrusions, controlled pinch points, breakaway or compliance features where suitable |
| Verification and recovery | Machine vision checks, grip confirmation, error states that prevent unsafe retries |
| Documentation | Risk assessment, safety function validation, operating instructions, training records |
Motionwell References (Where Cobots Meet Real Production)
| Project reference | Where the cobot is used | Why safety design is non-negotiable |
|---|---|---|
| Project P23078 (QA Lab Automation) | Cobot-assisted sample handling and station loading | Shared lab environments require clear zoning, predictable recovery, and traceable state transitions |
| Project P23022 / P23019 (EV Battery Disassembly Line) | Collaborative robot used at a vision-related station within a broader automated line | Mixed automation with high-risk workpieces makes risk assessment and safeguarding strategy essential |
Frequently Asked Questions
| Question | Answer |
|---|---|
| If I buy a cobot, do I automatically comply with ISO/TS 15066? | No. Compliance depends on the complete application: tooling, workpiece, speeds, zones, and validation evidence. The robot is only one part of the safety case. |
| Do collaborative cells always require no guarding? | Not necessarily. Many real cells are hybrid: collaborative behavior in one zone and physical safeguarding in another, depending on risks and tooling. |
| Is power-and-force limiting (PFL) always the best choice? | Not always. PFL is useful for close interaction tasks, but speed/separation monitoring or monitored stop can be a better fit when tooling or workpiece risks dominate. |
| What is the single most common mistake in cobot safety projects? | Treating safety as a late-stage add-on. Safety zoning, stop architecture, and recovery logic should be defined during concept design, not during commissioning. |
Implementing Cobot Safety: Practical Steps
For teams starting a cobot project, the gap between reading the standard and building a safe cell can feel large. Here is a practical sequence that Motionwell follows during robotics integration projects.
First, define the collaborative task boundary. Not every motion in a workcell needs to be collaborative. In many Motionwell projects the cobot operates at full speed during non-collaborative phases (for example, picking from a tray with no human nearby) and switches to a reduced-speed collaborative mode only when the operator intervenes for loading or inspection. Separating these phases in the safety concept simplifies the risk assessment and avoids unnecessarily limiting cycle time.
Second, involve the safety assessment early in mechanical design. End-effector geometry, workpiece edges, and fixture clamping forces all contribute to contact severity. Motionwell’s experience across medical device and electronics assembly projects shows that redesigning a gripper after commissioning costs several times more than addressing it during concept review. A simple change, such as adding a compliant finger tip or rounding a bracket edge, can shift a contact scenario from unacceptable to within ISO/TS 15066 transient limits.
Third, plan for validation evidence from day one. Regulated industries expect documented proof that safety functions perform as designed. This includes measured stopping distances, force and pressure readings at representative contact points, and scanner zone verification. Building the test plan alongside the safety concept, rather than writing it after installation, keeps the project timeline predictable and avoids rework during factory acceptance.
Conclusion
Safe human-robot collaboration is a design outcome. ISO/TS 15066 helps you choose an appropriate collaboration mode, execute a structured risk assessment, and implement validated safety functions that match your workflow.
If you are planning a collaborative robot application, contact us to review the safety concept before you lock the layout and tooling decisions.