Real-time Eco-Driving Control in Electrified Connected and Autonomous Vehicles Using Approximate Dynamic Programming

Connected and Automated Vehicles (CAVs), particularly those with a hybrid electric powertrain, have the potential to significantly improve vehicle energy savings in real-world driving conditions. In particular, the Eco-Driving problem seeks to design optimal speed and power usage profiles based on available information from connectivity and advanced mapping features to minimize the fuel consumption over an itinerary. This paper presents a hierarchical multi-layer Model Predictive Control (MPC) approach for improving the fuel economy of a 48V mild-hybrid powertrain in a connected vehicle environment. Approximate Dynamic Programming (ADP) is used to solve the Receding Horizon Optimal Control Problem (RHOCP), where the terminal cost for the RHOCP is approximated as the base-policy obtained from the long-term optimization. The controller was tested virtually (with deterministic and Monte Carlo simulation) across multiple real-world routes, demonstrating energy savings of more than 20%. The controller was then deployed on a test vehicle equipped with a rapid prototyping embedded controller. In-vehicle testing confirm the energy savings obtained in simulation and demonstrate the real-time ability of the controller.

Making the PI and PID Controller Tuning Inspired by Ziegler and Nichols Precise and Reliable

This paper deals with the design of a DC motor speed control implemented by an embedded controller. The design is simple and brings some important changes to the traditional Ziegler–Nichols tuning. The design also includes a novel anti-windup implementation of the controller and an integrated noise-reduction filter design. The proposed tuning method considers all important aspects of the control, such as pre-processing of the measured signals and filtering (to attenuate the measurement noise), time delays of the process, modeling and identification of the process, and constraints on the control signal. Three important aspects of designing PI and PID controllers for processes with noisy output on Arduino-type embedded computers are considered. First, it deals with the integrated design of the input filter and the controller parameters, since both are interdependent. Secondly, the method of setting the controllers from step responses by Ziegler and Nichols is modified for the case of digital signal processing (without drawing the tangent), while it recommends the suitability of its modification in terms of the use of both integral and static models. Third, the most suitable anti-windup solution for the given controller structure is proposed. In summary, the paper shows that an appropriate design of the embedded controller can achieve excellent closed-loop performance even in a noisy process environment with limited control signals.

Design and Development of an Embedded Controller for a Hydraulic Walking Robot WLBOT

In order to meet the requirement for the real-time of the hydraulic walking robot (WLBOT) and the stability of its movement, an embedded controller is proposed, which takes charge of multi-sensor information processing and signal output of the servo valve. The controller is capable of receiving control command and sending processed information while communicating with an embedded single board computer PCM-3365 via Control Area Network (CAN) bus at a 200 Hz frequency. In this paper, an appropriate interrupt cycle is selected and a 2 kHz high-speed control loop is run after we research the relationship between analog-to-digital converter direct memory access (ADC–DMA) interrupt cycle, data volume, and sampling rate. Significantly, the control strategy of WLBOT joint is introduced and a proportional-integral-derivative (PID) compound controller with velocity feedforward compensation (VFC) is realized. Meanwhile, the Chebyshev filtering algorithm is utilized to attenuate the vibration noise of joint signals. What’s more, an impedance controller is designed to gain better locomotion behavior and compliance in joint force control. Finally, the joint angle tracking and robot walking experiments are implemented, where the feasibility of the design and the validity of the control algorithm is verified. The results show that the PID velocity feedforward compensation controller can reduce the maximum tracking error by 39.13% and 71.31% in the knee and hip joint and the impedance control can reduce the standard deviation (SD) of the foot force by 36.06% and 72.79%.

Research on Embedded Controller of Hydraulic Vibrating Table Based on DSP

Background: Vibration control loop is the key technology adopt to improve the control performance of vibration table, which is set outside of the hydraulic vibration table servo control loop. However, the huge number of signal processing work prompts high demands on the calculation ability of the vibration controller. One kind of multi-CPU embedded vibration controller constructed by Digital Signal Processor (DSP) is proposed considering the working principle of the hydraulic vibration table and the Power Spectrum Density (PSD) reproduction process. The embedded controller consists of an acquisition unit, a calculation unit, and a monitoring unit distributes vibration control tasks to different processing unit to realize distributed algorithm calculations. Every processing unit uses dual-port memory to accomplish data interaction between each other. The development of the embedded controller provides a benchmark engineering case for the design of the hydraulic vibration table vibration controller. Objective: This article focuses on the development of the multi-CPU embedded vibration controller and the distributed calculations. Meanwhile, the power spectrum density experiment is carried out to verify the performance of hydraulic vibration embedded controller. Methods: 1) The structure of the hydraulic vibration table control system is given, that is, two closed-loop controls. The bandwidth of the system is further broadened by the vibration control of the outer loop. Besides, the accuracy of vibration control is also improved. Then, the development needs of the vibration controller is put forward according to the detail process of the power spectrum density replication. 2) An arithmetic processing unit is formed by using TI C2000 series DSP to calculate a large number of signal processing and a signal acquisition unit at a high speed. In order to improve signal processing efficiency, the signal acquisition unit is used to perform preprocessing calculations (data acquisition and filtering) and vibration control calculations in a distributed manner. 3) Processing speed is further improved by taking a full advantage of DSP software sources include lots of library functions and optimized assembly library functions. 4) The friendly operation of the controller and the safety monitoring of the experiment process are realized by the industrial computer served as the human-computer interaction unit. 5) Multi-CPU data sharing is achieved through using dual-port RAM to realize. Results: Through experiments, the developed embedded controller is fully estimated. The experiment shows that the developed hydraulic vibration table can realize real-time vibration control. Concerning the acceleration power spectrum density reproduction experiment, 256 acceleration response samples are calculated, and the update time is 4ms. The tracking accuracy of the time-domain waveform is controlled within 0.3%. Conclusion: The use of the developed embedded controller with a signal conditioning equipment can achieve real-time control of the hydraulic vibration table, but the performance of the embedded controller can be promoted in advance, and the performance improvement of the hydraulic vibration table embedded controller can be studied from the following aspects: 1)The Fourier calculation is executed by the acquisition unit to share the calculation workload of the calculation unit; 2) The computing unit uses a signal processor chip with better performance, although this will bring development difficulties; 3) The monitoring computer can use an embedded controller with superior performance instead of an industrial computer to reduce the size, improve the performance; 4) The DSP real-time operating system should be used and the task scheduling of vibration control experiments should be optimized.