# A Review of Coordinated Control Technology for Chassis of Distributed Drive Electric Vehicles
## 3 Two-Dimensional Coordinated Control Strategies for DDEV Chassis
### Longitudinal and Vertical Coordinated Control Strategies
on improving handling stability and optimizing traction and braking performance. The third category is oriented towards improving the overall vehicle energy efficiency while also considering dynamic performance. When a vehicle accelerates/decelerates, brakes, or drives on uneven roads, the significant coupling of longitudinal and vertical dynamics can easily lead to undesirable body attitudes such as pitch, directly affecting ride comfort and handling stability. These types of coordinated control strategies aim to effectively suppress vehicle body attitude changes and enhance ride smoothness by coordinating drive/braking systems and suspension systems. [PERSON] et al. [111] utilized in-wheel motors for the active control of vehicle pitch motion. They adopted a control strategy based on Lyapunov functions to actively suppress vehicle pitch. The core of this strategy was to leverage the coupling relationship between longitudinal forces and pitch motion. By precisely regulating the drive/brake torque of each in-wheel motor, the system actively generated a corrective moment. As a result, this method effectively attenuated the vehicle pitch's angular velocity and angular acceleration under various operating conditions. [PERSON] et al. [112] studied the coordinated smoothness control of active suspension and braking intensity. The study employed MPC to regulate the active suspension and regarded braking intensity as a disturbance or known input to the suspension control. By establishing a longitudinal-vertical coupled dynamics model to predict vehicle attitude changes during braking and actively adjusting the suspension parameters, the experimental results showed that this coordinated strategy could effectively suppress the \"nosedive\" phenomenon during braking, reduce the vertical acceleration impact, and improve ride comfort. Furthermore, [PERSON] et al. [113] proposed a method for suppressing transient suspension impacts based on vehicle speed control. After onboard sensors identify road bump excitations, this method uses fuzzy control to regulate the vehicle speed, simultaneously implements MPC for the ASS, and dynamically adjusts control weights to adapt to changes in vehicle speed. Simulation results demonstrate that, compared to sole suspension control, this coordinated strategy can improve vehicles' performance at different stages, further enhancing driving safety and ride comfort. Figure 8: Hierarchical cooperative control of driving/braking and suspension systems. Under extreme operating conditions (such as acceleration on low-adhesion surfaces or emergency braking), the coupling of longitudinal forces and vertical loads is crucial for the tire adhesion utilization rate and overall vehicle stability. These types of coordinated control strategies are dedicated to maximizing tire potential and enhancing vehicles' handling stability, traction, and braking performance by optimizing the vertical load distribution and precisely controlling longitudinal forces. [PERSON] et al. [114] implemented the integrated control of ASS and ABS based on a T-S fuzzy neural network model. Experimental results showed that this method could effectively shorten the braking time and distance and demonstrated a good, robust performance on rough road surfaces. Another study by [PERSON] et al. [115] adopted a fusion control strategy combining MPC and SMC, observed dynamic vertical loads on wheels using an Extended Kalman Filter (EKF), and addressed control signal delays using a Synchronous Phase Pre-compensation Calculator (SPPC). This ultimately achieved synchronized control of the drive system and active suspension, significantly enhancing the vehicle's extraction capability and driving stability on low-adhesion surfaces such as ice, snow, and sand. Longitudinal-vertical coordinated control for DDEV chassis not only focuses on enhancing their dynamic performance but can also improve overall energy utilization efficiency of the vehicle through methods such as optimizing energy recovery. [PERSON] et al.