Table of Contents
Defense robots are developed to perform missions such as mobility, surveillance, transportation, and search in environments that may be hazardous or difficult for people to access. Unlike robots operating in controlled industrial environments, defense robots may encounter changing terrain, temperature, vibration, and impact conditions. For this reason, stable operation and structural durability are important considerations when designing the drive systems that generate robot movement.
Walking robots, including bipedal and quadruped platforms, are repeatedly exposed to impact transmitted from the ground during movement. Robots equipped with manipulator arms may also experience different loads at each joint when lifting objects or operating equipment.
The actuators used in defense robots therefore need to do more than simply provide the required torque. Their design must also consider repeated loads, external impact, installation space, and the operating conditions expected during actual missions.
Operating Environments for Defense Robots
Key Summary Because defense robots may operate under changing terrain, climate, and mission conditions, both drive-system stability and durability must be considered.
Defense robots do not operate only on smooth factory floors or in controlled indoor environments. Depending on the mission, they may travel across dirt roads, gravel, slopes, uneven terrain, or other surfaces where vibration and impact occur continuously.
Under these conditions, the reducers, motors, and actuators that generate movement are repeatedly exposed to changing loads. Impact generated during movement can be transmitted to the drive system through wheels or leg joints, while the required torque can vary depending on robot posture, payload, and mounted equipment.
For this reason, evaluating individual component specifications alone may not be sufficient. The movement patterns and load conditions that occur after the components are integrated into the actual robot should also be considered.
The drive system needs to be configured according to the robot’s structure and mission requirements, and its ability to maintain stable operation under repeated movement and changing loads should be evaluated during the development process.
The Drive Characteristics Needed in the Actuator
Key Summary A defense robot actuator must reliably transmit the required torque under repeated impact and changing loads while remaining compact enough for integration into limited installation space.
Defense robots repeatedly accelerate, stop, change direction, and adjust posture during operation. In a quadruped walking robot, for example, the legs in contact with the ground must support the body while another leg moves. Impact generated when a foot contacts the ground is also transmitted through the joints.
The actuator must therefore be capable of delivering the required torque reliably even as the load changes.
The ability to respond to external forces is also important. When a robot contacts an obstacle or moves across uneven terrain, unexpected loads may be transmitted through the joint. A mechanical structure that distributes these loads rather than concentrating them in a limited area can help reduce stress on individual components.
Repeated operation over extended periods should also be considered. Defense robots may need to continue moving for long periods or repeatedly perform the same joint motions during a mission. Drive-system evaluation should therefore consider whether the actuator can maintain reliable operation over repeated cycles, rather than focusing only on initial or peak output.
The actuator’s dimensions and thickness also influence the overall robot design. Sensors, wiring, batteries, communication equipment, and control components must all be integrated alongside the drive system.
A thinner and more compact actuator can provide greater flexibility when using limited internal space and can make it easier to design compact joints and body structures.
Characteristics of Cycloidal Reduction Technology
Key Summary Cycloidal reduction technology can be considered for drive systems that experience repeated loads and impact because of its load-distribution characteristics.
A reducer lowers the motor’s rotational speed while increasing and transmitting the torque required to move the robot. In systems such as defense robots, where load conditions and external impact can change repeatedly during operation, the reducer’s transmission structure and durability are important design considerations.
A cycloidal reducer transmits torque through the engagement of curved profiles within its reduction mechanism.
Because the load can be distributed across multiple contact areas rather than concentrated at a single point, cycloidal reduction structures can be considered for robotic joints and mobile systems that experience repeated or changing loads.
This load-distribution characteristic can be useful when designing drive units for systems in which impact, posture changes, and varying external forces are part of the expected operating environment.
Bonsystems Drive Solutions
Key Summary Based on cycloidal reducer and actuator technology, Bonsystems develops drive solutions that can be considered for defense robots and other special-purpose robotic systems.
The Bonsystems BSR is a reducer lineup based on cycloidal reduction technology. As a component-level reducer, it can be considered for robot and mobile-platform designs in which the motor, housing, output structure, and other drive components need to be configured separately according to the system architecture.
The BCSA is an integrated actuator that combines a cycloidal reducer and a frameless motor in a slim, compact structure.
It can be considered for robot joints and special-purpose equipment where the motor and reducer need to be integrated while minimizing the overall size and thickness of the drive unit.
In defense robots, sensors, wiring, control electronics, batteries, and communication devices often need to be arranged within limited internal space. As a result, the size, thickness, and mounting method of the drive unit can have a significant effect on the overall robot design.
An integrated actuator such as the BCSA can provide greater flexibility when arranging the drive system within a confined joint or body structure.
The BSR and BCSA are designed around characteristics such as compact structure, torque transmission, multiple reduction ratio options, and design flexibility for different applications.
However, because defense robots differ significantly in mission profile and operating environment, product selection should consider not only required torque and dimensions but also actual load conditions, repeated operation, impact, and mounting requirements.
Bonsystems evaluates the potential application of the BSR and BCSA according to factors such as robot joint structure, movement method, payload, installation space, and drive requirements.
Key Takeaways
The drive system of a defense robot is not defined simply by how much force it can generate. It must also maintain reliable movement under changing loads, repeated impact, and varying operating conditions.
Because terrain, temperature, vibration, posture, and mission conditions may change during operation, suitability cannot always be determined from rated specifications alone.
When selecting a reducer or actuator, developers should consider the robot’s actual mission, mounting structure, expected load, repeated-operation conditions, and installation environment together.
Cycloidal reduction technology distributes load across multiple contact areas within the reduction structure, making it one option for robotic and mobile drive systems exposed to repeated loads and impact.
Bonsystems offers the BSR as a component-level cycloidal reducer and the BCSA as an integrated motor-and-reducer actuator, allowing different drive configurations to be considered according to robot joint structure, movement method, payload, and available installation space.
Frequently Asked Questions (FAQ)
Q1. What should be considered when selecting an actuator for a defense robot?
A. Required torque and operating speed should be determined according to factors such as robot weight, joint structure, movement method, payload, and mounted equipment. Actuator dimensions, installation space, repeated loads, impact conditions, and expected operating duration should also be considered.
Q2. Why is reducer structure important in environments with repeated impact?
A. Impact generated during movement or walking is transmitted through the joints to the drive system. A reducer structure that distributes load across multiple contact areas can help reduce local stress concentration and support stable torque transmission under changing load conditions.
Q3. Why is a slim actuator important in defense robot design?
A. The drive system must share limited internal space with sensors, wiring, batteries, communication devices, and control components. Reducing actuator thickness and overall dimensions can provide greater flexibility when arranging these components and designing compact joints or body structures.
Q4. What should be reviewed first when selecting a drive unit for a defense robot?
A. The required torque, speed, and motion range should first be defined according to the robot’s mission and intended movement. The reducer and actuator configuration can then be reviewed based on installation space, expected loads, repeated operation, impact conditions, and system architecture.
Q5. How can the Bonsystems BCSA be considered for defense robot applications?
A. The BCSA combines a frameless motor and a cycloidal reducer in a slim, compact actuator structure. It can be considered for robotic joints and special-purpose systems where the drive unit, sensors, and wiring need to be integrated within limited installation space.
References
• [1] Bonsystems Official Website — https://www.bonsystems.com
• [2] Korea Institute for Robot Industry Advancement (KIRIA) — https://www.kiria.org
• [3] Korea Association of Robot Industry (KAR) — https://www.irobotics.or.kr
• [4] Korea Institute of Robotics & Technology Convergence (KIRO) — https://www.kiro.re.kr
• [5] Ministry of Trade, Industry and Energy – Robot Industry Policy — https://www.motie.go.kr
Bonsystems
A specialist in Pinless cycloidal reducers and actuators
