Agility Robotics Cassie — Specs & Review
Specifications
| Brand | Agility Robotics |
|---|---|
| Model | Cassie |
| Year | 2017 |
| Category | Humanoid |
| Autonomy | semi-autonomous |
| Environment | both |
| Weight | 32 kg |
| Dimensions | 40cm L × 50cm W × 90cm H |
| Connectivity | WiFi, ROS |
| Country of origin | US |
Key features
- Bird-inspired spring-mass legs
- 32 kg lightweight build
- 5km run completed in 53 minutes
- Bipedal locomotion specialist
- Predecessor to Digit
- ROS-compatible research platform
- Leg-only, no torso or arms
What is it?
Agility Robotics Cassie is a bipedal locomotion research robot — lower body only, modelled on bird anatomy — developed as the foundational platform that led to the creation of Digit.
Who is it for?
Cassie was sold to university and research institution robotics labs studying bipedal locomotion, dynamic walking, reinforcement learning for locomotion, and legged robot control.
Key specs
- Weight: 32 kg
- Height: ~90 cm (pelvis height)
- Configuration: legs + pelvis only, no torso or arms
- Achievement: 5km run in 53 minutes (2021)
- Leg design: spring-loaded, bird-inspired
- Platform: ROS-compatible
How it compares
Vs Boston Dynamics Atlas: Cassie is a lower-body-only research platform; Atlas is a full humanoid. Cassie's spring-mass leg design is more energy efficient than hydraulic systems, inspiring subsequent electric humanoid leg designs across the industry.
Limitations
- Lower body only — no manipulation capability
- Discontinued as commercial platform
- Requires significant engineering expertise to operate
- Research platform — not suitable for operational task deployment
FAQ
What is Agility Robotics Cassie?
Cassie is a bipedal research robot developed by Agility Robotics in 2017 as the precursor to Digit. Cassie is a lower-body-only robot — legs and pelvis with no torso, arms, or head — designed specifically for bipedal locomotion research.
Is Cassie still available?
Cassie was discontinued as a commercial research platform following the launch of Digit. Several research institutions that purchased Cassie systems still use them for locomotion research.
What are Cassie's key specs?
Cassie weighs 32 kg, is approximately 90 cm tall at the pelvis, walks and runs bipedally, completed a 5km run in 53 minutes in 2021, and uses spring-loaded legs modelled on the anatomy of a bird.
Why was Cassie significant?
Cassie demonstrated that bird-inspired spring-mass bipedal locomotion could achieve robust, energy-efficient walking and running on real-world terrain. It became one of the most studied bipedal robot platforms in academic robotics research.
How does Cassie differ from Digit?
Cassie is a lower-body-only locomotion research platform with no torso, arms, or manipulation capability. Digit adds a full torso, arms, and hands, making it a complete humanoid capable of manipulation and logistics tasks.