Short Answer:

Types of synthesis in mechanism design are mainly divided into three categories: path generation, motion generation, and function generation. These types define the purpose for which a mechanism is designed and help determine its configuration, dimensions, and link arrangement.

In simple terms, synthesis types describe how a mechanism is planned to work. Whether it needs to make a point move along a path, produce a desired motion of a body, or maintain a fixed relation between input and output — all are covered under different types of synthesis.

Detailed Explanation :

Types of Synthesis

In mechanical engineering, synthesis is the process of designing mechanisms that can perform a desired function or motion. Once the motion or path is decided, the next step is to determine the correct type of synthesis that suits the requirement. The type of synthesis helps in defining the relationship between motion, path, and function of the mechanism.

Generally, there are three main types of synthesis used in mechanism design:

1. Path Generation
2. Motion Generation
3. Function Generation

Each type of synthesis has its own purpose, design approach, and method of application. These types help mechanical engineers to create mechanisms that perform accurately and efficiently according to the need of the machine.

1. Path Generation
   Path generation synthesis focuses on designing a mechanism in such a way that a specific point on one of its links traces a desired path in space.
   In simple words, it means ensuring that one particular point follows a defined curve or line when the mechanism moves.

For example, in a robotic welding arm, the welding torch must move along a specific path to join parts accurately. The mechanism must be designed to ensure that the tip of the torch moves along the exact curve required.

In path generation, only the motion of a single point is controlled; the orientation of the link (the direction it faces) is not considered. This type of synthesis is important when the accuracy of the point’s movement is more critical than the orientation of the link itself.

Applications of path generation include:

• Robot arm design
• Drawing or cutting machines
• Material handling linkages
• Sewing machines and printing devices

Thus, path generation helps in creating mechanisms where a fixed point needs to follow a desired route.

2. Motion Generation
   Motion generation synthesis involves designing a mechanism so that a rigid body moves through a series of specified positions.
   Unlike path generation, here both the position and orientationof the body are controlled.

For instance, in a pick-and-place robotic arm, the end-effector must not only reach certain positions but also maintain proper orientation to grip and place the object correctly. Similarly, in aircraft landing gear mechanisms, the wheel must fold and unfold along specific angles and directions.

Motion generation synthesis is more complex because it needs to satisfy both the movement and the rotation of the link. It ensures that the mechanism can move an object or part from one configuration to another smoothly and accurately.

Applications of motion generation include:

• Robotic manipulators
• Aircraft landing gear mechanisms
• Lifting and positioning equipment
• Folding and unfolding mechanisms

This type of synthesis is essential where both position and angle control are important.

3. Function Generation
   Function generation synthesis deals with creating a mechanism that provides a specific mathematical relationship between the input and output motions.
   In other words, the goal is to design a mechanism such that the output motion varies according to a desired function of the input motion.

For example, in a steering mechanism, the turning angle of the wheels is a specific function of the steering wheel rotation. Similarly, in a governor mechanism, the speed of the engine shaft determines the position of the flyweights through a defined relationship.

In function generation, neither the path of a point nor the body orientation is the focus. The primary objective is the relationship between the input and output variables.

Applications of function generation include:

• Cam mechanisms
• Gear trains
• Governors
• Linkages converting rotary motion into non-uniform motion

This synthesis is important where the mechanical motion conversion must follow a specific law or formula.

4. Comparison of the Three Types
   To summarize the main differences between the types of synthesis:

• Path generation: Controls the path of a point.
• Motion generation: Controls both position and orientation of a body.
• Function generation: Controls the input-output motion relationship.

Each of these types serves a unique purpose and may sometimes be combined in complex mechanism designs. For example, a robotic mechanism might use both motion generation and function generation principles to achieve precise movement and force control.

5. Importance of Identifying the Right Type
   Choosing the correct type of synthesis is very important in mechanism design. If the wrong type is selected, the mechanism may not perform the required motion accurately.
   Proper synthesis ensures that:

• The mechanism performs the intended function.
• Energy is used efficiently.
• Motion is smooth and precise.
• Wear and vibration are minimized.

Modern tools such as CAD and simulation software help engineers test and optimize these designs before manufacturing.

Conclusion:

Types of synthesis form the foundation of mechanism design. The three major types—path generation, motion generation, and function generation—each focus on different motion requirements. Path generation deals with the movement of a point, motion generation involves both position and orientation, and function generation focuses on the relationship between input and output. Correct selection and application of these synthesis types lead to efficient, reliable, and high-performing mechanical systems used in industries, robotics, and machinery.