HVAC-Performance in EVs

The management of the air conditioning system, which is integrated into the heating, ventilation and air conditioning (HVAC) system, plays an important role in the context of the range of electric vehicles (EVs). Thermal management in EVs is a complex effort: the challenges go beyond thermal comfort in the interior, as the system must also keep critical powertrain components within a safe operating temperature corridor.


 

Thermal Management of E-Vehicle Batteries

Electric vehicles (EVs) are the future of environmentally friendly transportation. The global market for electric cars has seen a steady increase in sales over the last decade. The safety issues associated with the use of lithium-ion batteries in electric vehicles grow in importance as these batteries are becoming more powerful, charging times reduce and the size of battery packs increase to maximize range.
 

NVH Measurement in Vehicles

NVH measurements (Noise, Vibration, Harshness) are an important component in the development of cars. They include the analysis and evaluation of a vehicle's sound and vibration behavior under various conditions. If a multi-channel data acquisition system is used for noise and vibration measurement, a comprehensive noise analysis of specific noise sources inside and outside the vehicle can be carried out. The interior noise in the passenger compartment, the pass-by noise and the sound power of engines and fans, among other things, are measured.

Current Measurement in EVs

In the world of hybrid and electric vehicles (EVs), accurate current measurement plays a central role in various critical development and usage matters. Whether it's evaluating power consumption or analyzing charging processes, high-precision current measurement is an essential part of the testing process. There are various techniques for measuring electrical current, each with their own advantages and optimal application scenarios. Some of the most common current measurement techniques are presented on the following page.

Power Measurement in EVs

Battery Testing for EVs

Extensive tests and inspections are crucial in the development of batteries for electric vehicles (EVs). They help to determine the load limits of battery cells, modules and complete battery packs. They include long-term tests in climatic chambers as well as load tests with charging and discharging cycles. During these tests, continuous monitoring of the cell voltage and temperature is required for each individual battery cell. In addition, crash tests, battery drop tests, penetration tests, pressure, bending and vibration tests and misuse tests are carried out.

Vehicle Dynamics

Vehicle dynamics is concerned with analyzing the movement sequences of the vehicle. It includes individual factors such as acceleration, braking, handling, ride comfort and stability. In a broader sense, it also includes recognizing and predicting vehicle reactions to various influences such as steering, road bumps and aerodynamic forces. Vehicle dynamics are crucial for the design and optimization of cars in terms of safety, efficiency and performance, as well as for driving stability, manoeuvrability and comfort.

 

Measuring Wheel Forces and Torques

The determination of wheel force and wheel torque is essential for the development of modern vehicles. A common method of measuring drive torque is to use strain gauges on the original output shaft. Another equivalent method is measurement via an explicit torque sensor mounted between the rim flange and wheel hub. A wheel force and torque transducer is required to measure forces and torques with high precision.


 

Torque Vectoring

Torque vectoring is being used more and more frequently for chassis tuning in modern (e)-vehicle architectures: Drive and braking torques are differently adjusted at the individual wheels. The basis for this is vehicle dynamics, dealing with the lateral dynamics of the vehicle, which relates to driving stability, lateral slip, yaw and roll. It is also subdivided into longitudinal dynamics and vertical dynamics, which cover driving, braking and ride comfort. Drive and brake slip are investigated in the longitudinal direction of the vehicle, which can also improve driving and braking efficiency.

Measurements on Vehicle Steering Systems

A vehicle's steering system is a crucial element for safety, driving dynamics and driving comfort. It consists of various components to steer the vehicle safely. Faulty steering can lead to dangerous situations or accidents, which is why the proper functioning of steering systems is of crucial importance. To ensure that steering systems are working properly, measurements and tests with steering sensors are essential. There are global standards to guarantee that steering behavior measurements are uniform and reproducible.

Wireless Wheel Speed Detection

Autonomous sensors measure various factors influencing the wheel speed independently of the vehicle and without any mechanical influence. This so-called wheel slip can be caused by the vehicle's own driving behavior. A distinction is made between a locked wheel - the wheel is stationary but the vehicle is still moving - or a spinning wheel - the wheel is already moving but the vehicle is still stationary. Assistance systems such as ABS or ESP intervene in the vehicle control system to prevent wheel slip. To do this, you need to know the exact moment of wheel slip.

Vehicle Brake Performance

Measuring brake performance is an essential part of efforts to improve road safety. This involves measuring and processing a wide range of parameters such as brake pressure, brake force, pedal travel, temperature at the brake discs, vibrations at the brake calliper and brake noise.
Assistance systems (ADAS) such as ABS and ESP continuously monitor vehicle dynamics and intervene during braking to bring the vehicle to a controlled stop while remaining in the lane. They also need to be closely monitored.

Road Load Data Acquisition (RLDA)

Road Load Data Acquisition (RLDA) collects and analyzes data that reflects the behavior of vehicles under real-world conditions. The data collected is used to simulate the vehicle during the development process. It is also used to develop a test program for component testing on the test bench.





 

Vehicle Endurance Testing

Endurance testing of vehicles is an essential part of the automotive industry's efforts to produce reliable, safe and high-quality vehicles. They represent a critical phase in the development and testing of motor vehicles. The primary purpose of endurance testing is to simulate the wear and tear that a vehicle will experience throughout its lifetime. This test phase helps manufacturers to accurately assess the safety, reliability, durability and overall performance of a vehicle under different conditions.

 

Advanced Driver Assistance Systems and Autonomous Driving

The automotive industry is in the midst of a revolutionary change that is fundamentally altering our understanding of driving. The drivers of this change are Advanced Driver Assistance Systems (ADAS) and Autonomous Driving (AD). These technologies are designed to increase safety, optimize traffic flow and ultimately usher in a new era of driving.



 

Pass-by Noise Measurement

Vehicle pass-by measurements record the sound level and acoustic characteristics of a vehicle as it passes a certain point.


 

Sound Power

Sound power is the sound energy that a component or machine emits in all directions. It is independent of distance and cannot be measured with a simple sound level meter.
 

Drive Train Efficiency

Efficiency is a paramount consideration in the development and optimization of electric vehicles (EVs) powertrains. To evaluate and improve efficiency, detailed measurements of speed, torque, current, voltage, and power are essential components of the testing process.

Torque Measurement

In the realm of assessing mechanical performance, whether on a stationary test bench or during dynamic driving tests, the measurement of speed and torque is paramount. These parameters provide critical insights into how a system operates, making them indispensable for performance evaluation.