Project

# Title Team Members TA Documents Sponsor
41 OmniGrasp: VLA-Driven Mobile Manipulator with Custom-Built 7-DOF Arm and Mecanum Chassis
 Dayu Xia
Shurong Wang
Tongning Zhang
Yaofang Ji
 other1.pdf
 Piao Chen
# Project Proposal for ECE 445

**Project Title:** OmniGrasp: VLA-Driven Mobile Manipulator with Custom-Built 7-DOF Arm and Mecanum Chassis

**Team Members:** Tongning Zhang, Shurong Wang, Dayu Xia, Yaofang Ji

### Problem
In complex daily or industrial environments, standard robotic manipulators are fundamentally limited by a stationary workspace and rigid, pre-programmed trajectories. Furthermore, commercial 7-DOF robotic arms are often prohibitively expensive, overly heavy, or difficult to seamlessly integrate with custom mobile platforms. There is a critical need for an intelligent, highly integrated mobile system that combines a custom-manufactured, lightweight manipulator with autonomous navigation and high-level reasoning capabilities driven by natural language commands.

### Solution Overview
Our solution is a mobile robotic manipulator capable of navigating dynamic environments to execute complex, multi-stage grasping tasks. The hardware consists of an omnidirectional Mecanum wheel chassis paired with a custom-designed and manufactured 7-Degree-of-Freedom (7-DOF) robotic arm and a versatile gripper. To achieve optimal weight distribution and payload capacity, the 7-DOF arm will be fully modeled in CAD and fabricated in-house using a combination of 3D printing and precision machining. The system operates on a hierarchical control architecture. At the highest level, a Vision-Language-Action (VLA) model running on an edge computer interprets natural language commands and plans the necessary mobile navigation and manipulation sequences. The system seamlessly coordinates the base movement and the custom arm's inverse kinematics to approach and grasp target objects.

### Solution Components
* **Mechanical Design and Fabrication Subsystem:** The physical structure of the 7-DOF arm, including custom-engineered links, joint enclosures, and motor mounts, designed via CAD software and manufactured using 3D printing and CNC machining to ensure structural integrity and optimal payload-to-weight ratio.
* **Perception and High-Level Planning Subsystem:** An edge computer hosting a Vision-Language-Action (VLA) model designed to interpret natural language commands (e.g., "Navigate to the table and grasp the red cube") and plan comprehensive task sequences.
* **Low-Level Control Subsystem:** A microcontroller dedicated to executing omnidirectional kinematics for the Mecanum chassis and inverse kinematics with PID motor control for the 7-DOF arm's precise movement.
* **Mobility and Actuation Subsystem:** The integrated hardware platform comprising the Mecanum wheel base for unconstrained floor movement and the custom 7-axis robotic joint motors equipped with a gripper for dexterous physical manipulation.
* **Feedback Subsystem:** A sensor feedback loop integrating vision or odometry for base positioning, alongside torque or current sensors designed to provide grasp verification during object manipulation.

### Criteria of Success
* The custom-manufactured 7-DOF arm must maintain structural integrity under its designated maximum payload without significant mechanical deflection or structural failure.
* The Mecanum chassis must successfully navigate to designated locations based on the VLA model's planning.
* The high-level VLA model must accurately interpret natural language commands to plan correct, multi-stage task sequences involving both mobility and manipulation.
* The 7-DOF robotic arm must demonstrate the ability to calculate and execute smooth trajectories to reach target objects, effectively utilizing its redundant joints.
* The gripper must successfully grasp and manipulate various target objects based on their geometry without dropping them.

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