Robots today are being used across industries and environments to automate tasks, enhance capabilities, and improve efficiency. Its power source is a key component that determines how well a robot can operate. According to Statista, the number of domestic household robots sold worldwide is expected to reach 41.2 million by 2023, up from 18.4 million in 2018. Selecting the right type of power system is crucial based on the robot’s size, function, and operating environment. This article will provide an in-depth look at the diverse power sources available for powering robots.
Common Robot Power Sources
Various power systems are used today to energize different types of robots. Some of the most common options include:
Batteries
Batteries are one of the most ubiquitous power sources used for robots. They provide portable energy storage in a small form factor. Different battery types used in robots include:
- Lead-acid – Lead-acid batteries are cost-effective and provide high surge currents. However, they are heavy and have a limited cycle life. Best suited for large industrial robots.
- Lithium-ion – Li-ion batteries offer high energy density, low weight, and long lifespans. They are commonly used in consumer drones and household robots.
- Nickel-metal hydride – NiMH batteries provide good energy density at low costs. But they suffer from memory effects. Useful for education and hobby robots.
Rechargeable batteries allow robots to operate untethered for reasonable durations. Proper recharging infrastructure must be provided to ensure continuous operation.
Fuel Cells
Fuel cells generate electricity through an electrochemical reaction using hydrogen and oxygen. Some ways fuel cells are used to power robots:
- Proton exchange membrane – PEM fuel cells offer higher power density and quickly supply peak power demands, making them suitable for humanoid robots.
- Solid oxide – SOFCs allow operation on different fuels and are resistant to shock/vibration. Used in military and space robots.
- Microbial – MFCs use bacteria to generate low levels of electricity from organic matter. Useful for small aquatic robots.
Fuel cells can provide long runtimes to robots but require storage and delivery systems for fuel.
Tethers
Tethered cables can continuously supply power to robots directly from an external source. This approach provides unlimited run time without onboard energy storage.
Some examples of tethered robots include:
- Bomb disposal robots – Allows them to operate safely from a distance.
- Factory assembly robots – Eliminates battery recharging downtime.
- Underwater ROVs – Let them stay submerged indefinitely.
However, tethers limit the robot’s operating radius due to cable length constraints.
Pneumatics
Pneumatic power uses pressurized gas to activate mechanisms like robotic limbs/joints. Some ways it is leveraged in robotics:
- Does not require heavy motors or gearing systems, allowing lightweight designs.
- Gas compressors can be located remotely while tubing routes air to actuators.
- Fast responsiveness from the direct drive.
Drawbacks include expensive compressors, air leakage, and challenging control.
Hydraulics
Hydraulics use pressurized liquid to drive motors, cylinders, and actuators in robots. Benefits include:
- Higher power density than pneumatics.
- Good for heavy lifting applications due to high force output.
- Components provide damping and shock absorption.
Limitations include complex plumbing, fluid leakage, and compressibility issues.
Solar Power
Photovoltaic solar panels can directly convert sunlight into electricity to charge batteries or run actuators. Especially useful for:
- Outdoor robots and drones to extend operational time.
- Underwater robots where solar energy can be leveraged in the top water layer.
- Spacecraft and planetary robots where solar is abundant.
Reliance on solar exposure and energy storage for dark conditions are key considerations.
Choosing the Right Power Source for Home Robotics
Factors like size, weight, safety, ease of use, and operating duration are important for selecting the optimal power system for home and personal robots.
Small Domestic Robots
For compact home robots like robot vacuums and lawnmowers, rechargeable lithium-ion batteries offer the best balance of energy density, lifespan and convenience. Features like automated docking stations make charging straightforward.
Entertainments Robots
Larger interactive robots for entertainment need to balance weight, run time and power demands. Lithium-polymer batteries coupled with efficient motors provide full-day operation between charges for many entertainment robots.
Telepresence Robots
Remotely controlled telepresence robots need to optimize uptime since they are driven from afar. Hybrid power systems combining high-density Li-ion batteries with backup fuel cells or fast-charging features help maximize availability.
Robotic Limbs
Prosthetic robotic limbs need to mimic natural movements requiring peak power delivery. Compact pneumatic artificial muscles provide simplicity and responsiveness for accurately reproducing human motions.
Robot Toys
For robot toys, safety, cost and runtime are key priorities. Nickel-cadmium or NiMH batteries are inexpensive options that provide up to an hour of fun between charges. Solar cells can also supplement battery life.
Underwater Robots
For home pool robots, tethers provide unlimited underwater runtime for cleaning. Onboard batteries allow limited untethered operation for accessing the entire pool. Wireless inductive charging plates make recharging convenient.
Considering a robot’s physical capabilities, operational environment and usage patterns is key for identifying an optimal power system. Consulting robotics experts can provide guidance for special needs.
Conclusion
There is a wide variety of power sources available today for energizing robots across industries and scales. Batteries, fuel cells, pneumatics, hydraulics, solar power and tethers each have their own advantages and limitations based on the robot application. For home and consumer robots, rechargeable lithium-ion batteries often provide the best combination of portability, runtime, and convenience. However specialized needs may benefit from alternate power systems. Understanding the options allows matching the power supply with the robot’s physical and performance requirements for optimal operation.