Robotic Leg Cardan Drive for Continuous Phalange Swinging
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Solution Overview
Problem
Existing robotic legs require continuous intermittent movements of electric motors due to changes in direction, leading to reduced speed, increased energy consumption, and uneven wear of components.
Innovation Solution
A robotic leg design utilizing an articulated joint and cardan mechanism to transfer rotary motion to swinging motion, allowing for uninterrupted movement and reducing component wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a rotary electric motor is used to drive leg phalanges through gear or toothed belt transmission, then the swinging motion can be achieved, but the motor must continuously perform short intermittent alternating movements due to direction changes, reducing speed and increasing energy consumption
Solution Approach 1:
A linear actuator is introduced as an intermediary between the rotary motor and the leg phalange. The linear actuator converts the motor's continuous rotary motion into linear motion, which then drives the phalange through a mechanical linkage. This intermediary mechanism eliminates the need for the motor to reverse direction continuously, allowing uninterrupted motion and reducing energy consumption while maintaining speed.
Solution Approach 2:
The traditional gear or toothed belt transmission system is replaced with a linear actuator mechanism. Instead of using the motor directly to rotate the phalange through mechanical transmission, the system substitutes this with a linear actuator that pushes or pulls a rod attached to the phalange, achieving the swinging motion without intermittent motor movements.
2Ease of operation
If the electric motor continuously changes rotation direction to drive leg phalanges, then the swinging motion is achieved, but uneven wear of transmission components occurs, reducing lifetime
Solution Approach 1:
The linear actuator serves as a mediator that decouples the motor from the phalange directly. The motor continuously drives the actuator in one direction, and the actuator converts this continuous motion into the required swinging motion of the phalange through linear movement. This eliminates repeated direction changes in the motor, preventing uneven wear of transmission components and extending their lifetime.
Solution Approach 2:
The gear or toothed belt transmission system that causes uneven wear is replaced with a linear actuator mechanism. The linear actuator pushes or pulls the rod attached to the phalange, achieving the swinging motion without the intermittent reversals that cause wear in traditional mechanical transmission systems.
3Ease of operation
If a hydraulic or pneumatic linear motor is used to push or pull the rod attached to the leg phalange, then the swinging motion is achieved, but the system becomes more complex
Solution Approach 1:
The complex hydraulic or pneumatic linear motor system is replaced with a simpler electric linear actuator. The electric actuator uses an electric motor combined with a screw mechanism or similar linear conversion mechanism, which is less complex than hydraulic or pneumatic systems while achieving the same swinging motion capability through pushing or pulling the rod.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables smoother and faster robot movement with prolonged component lifetime by eliminating intermittent motor movements.
Implementation Method 1
The cardan mechanism comprises the driving carrier, the driven carrier, the cross and the fork. The driving carrier is connected via the shaft of the electric motor to the electric motor so that the driving carrier of the cardan mechanism is driven by the electric motor. The driven carrier is rotatably connected with the first phalange, the cross being disposed between the driving carrier and the driven carrier such that the cross is rotatably connected with the driving carrier and rotatably connected with the driven carrier.
Data Source
AI summary
A robot leg comprises at least two phalanges (1, 2) connected to each other by articulated joint (4). The robotic leg further comprises the electric motor (6A) with the shaft (61A), the cardan mechanism (7A) and the rod (8A), wherein the electric motor (6A) with the shaft (61A) is arranged in the first phalange (1), the cardan mechanism (7A) comprises the driving carrier (71A), the driven carrier (72A), the cross (73A) and the fork (74A). The driving carrier (71A) is connected via the shaft (61A) of the electric motor (6A) with the electric motor (6A), so that the driving carrier (71A) of the cardan mechanism (7A) is driven by the electric motor (6A), the driven carrier (72A) is connected with the first phalange (1), the cross (73A) is arranged between the driving carrier (71A) and the driven carrier (72A), the cross (73A) being rotatably connected with the driving carrier (71A) and rotatably connected with the driven carrier (72A), the fork (74A) being rotatably connected with the cross (73A). The rod (8A) is connected at one end thereof with the fork (74A), and at the other end thereof with the second phalange (2) by means of articulated joint (4A). The coupling of the electric motor (6A) with the cardan mechanism (7A) and with the rod (8A) connected with the second phalange (2) ensures the transmission of the rotational movement of the electric motor (6A) to the swinging movement of the fork (74A) in the longitudinal plane with the axis of rotation at the centre of the cross (73A), and thus transferring the swinging motion of the fork (74A) to the linear motion of the rod (8A), which ensures the swinging motion of the second leg phalange (2) about the axis of articulated joint (4).