FAQ
Inertial+: The Core of Everything We do
Inertial sensors are the foundation of all TDK’s positioning solutions. They are always-on positioning sensors that provide continuous and reliable 3D positioning information. Inertial sensors have become a key enabler in a wide variety of applications, such as wearables and intelligent vehicles. Combined with other absolute positioning sources like geomagnetic or wireless signals, these sensors enable accurate and affordable relative positioning in all environments.
No, a single location technology cannot provide accurate and reliable location information in all environments. At TDK Trusted Positioning, we gather data from all available sources to filter out erroneous measurements and determine the most accurate position.
Our objective is to enable high-quality positioning performance at a price feasible for large-scale implementation, regardless of the application or use case.
VENUE creates an indoor positioning solution using a mobile device and an indoor map. By leveraging built-in inertial and magnetic sensors, VENUE tracks the movement of a person or wheeled platform indoors using geomagnetic positioning, inertial navigation, and other wireless signals. By integrating all sources of positioning technology, VENUE achieves an average accuracy of 1-3 meters.
RIDE obtains accurate positions, orientations, and rider dynamics of 2-wheeled platforms by integrating inertial sensors and GNSS inputs. Low-cost MEMS sensors such as accelerometers and gyroscopes are always-on and detect movement, driver dynamics, accurate drop-off position and fall detection. When used with GNSS updates, these inertial sensors can filter GNSS multipath and save power. Our INS algorithms in RIDE are tuned and adapted for 2-wheel vehicle dynamics.
TRACK uses inertial MEMS sensors and GNSS to provide enhanced vehicle positioning in challenging environments. The accelerometers and gyroscopes in the inertial core continuously track the relative movement of the vehicle and use GNSS information as absolute updates when available. In areas where GNSS becomes unreliable, the inertial core filters out erroneous data and provides reliable positioning without GNSS. Calibration and misalignment are automatically determined through typical driving motion.
AUTO achieves high accuracy, high integrity, and lower-cost positioning for autonomous wheeled platforms by integrating an automotive-grade IMU, vehicle speed, high-accuracy GNSS, and perception sensors, all accurately timed to provide more accuracy than our TRACK product. The inertial navigation, combined with optional imaging radar and GNSS, enables decimeter-level positioning in challenging GNSS environments, including urban and residential areas. TDK Trusted Positioning’s world-class inertial navigation software has improved INS-only performance by a factor of ten times over previous generations.
The term “dead reckoning” comes from the nautical tradition, where it was used to describe a navigation technique that involved estimating a vessel’s current position based on its previously known position and course, combined with speed and time measurements. This method assumes that the object’s motion is constant, and there are no external forces acting on it, such as wind or currents.
In the context of inertial navigation systems, dead reckoning is achieved through the use of accelerometers and gyroscopes. These sensors measure the object’s linear accelerations and angular velocities, respectively. By integrating these measurements over time, the system continuously updates its estimated position, velocity, and attitude.
Inertial Navigation Systems (INS)
Inertial Navigation Systems (INS) refer to the algorithms used to transform raw accelerometer and gyroscope data into positioning information. INS operates based on relative positioning, meaning it relies on a reference point or system, such as GNSS (Global Navigation Satellite System), to determine accurate relative positioning.
INS utilizes the measurements from accelerometers and gyroscopes to track the movement and orientation of a device or vehicle. By integrating these sensor data over time, the system calculates changes in position and orientation. However, since INS is relative and not absolute, it requires an initial reference point or system to establish the starting position accurately.
INS is a critical component that works in conjunction with other positioning technologies, such as GNSS. The inertial sensors, including accelerometers and gyroscopes, continuously track movement and provide relative positioning information. This information combined with absolute positioning data from GNSS or other sources to enhance accuracy and reliability in challenging environments.
GNSS provides absolute positioning information based on signals from satellites, but it can face limitations in certain environments, such as underground, high foliage, urban canyons or tunnels. INS, on the other hand, can provide continuous positioning updates even when GNSS signals are unavailable or unreliable. By integrating the data from inertial sensors and GNSS, TDK Trusted Positioning solutions achieve more robust and accurate positioning in a variety of challenging scenarios.
The use of INS in TDK Trusted Positioning solutions brings several benefits, including:
- Continuous positioning: INS provides always-on positioning information, ensuring uninterrupted tracking and navigation.
- Enhanced accuracy: By integrating inertial sensor data with other positioning technologies, the overall accuracy of the system improves.
- Reliable positioning in challenging environments: INS can compensate for GNSS signal blockages, position drift or disruptions, enabling reliable positioning in urban canyons, tunnels, or other challenging environments.
- Lower power consumption: Inertial sensors are low-power and can conserve power by activating GNSS only when necessary, reducing overall power consumption in devices or vehicles.
INS alone cannot provide absolute positioning information. It is a relative positioning system that requires an external reference, such as GNSS, to establish an accurate starting point. However, INS can significantly enhance positioning accuracy and reliability when integrated with other absolute positioning technologies in TDK Trusted Positioning solutions.
Global Navigation Satellite Systems (GNSS)
The Global Navigation Satellite System (GNSS) refers to a system composed of multiple satellite constellation maintained by various countries. GPS (Global Positioning System) is the US system. Galileo in the European Union positioning system. GLONASS is maintained by Russia and Beidou is China’s system. All provide global coverage. Together they are known as GNSS. GNSS enables receivers to determine accurate and absolute positioning by receiving signals from these satellites, typically simultaneously.
A GNSS receiver calculates its position by receiving signals from multiple satellites in the constellation it has line of sight visibility to. By analyzing the time it takes for signals to reach the receiver from different satellites, the receiver can triangulate its position on the Earth’s surface.
Several factors can impact the accuracy and availability of GNSS positioning:
- Satellite visibility: A GNSS receiver needs to have a clear line of sight to multiple satellites to calculate accurate positioning. Obstructions such as buildings or natural obstacles can hinder satellite visibility and affect accuracy.
- Signal quality: The quality of the received satellite signals plays a crucial role. Interference or signal degradation can impact the accuracy of positioning information.
- Atmospheric conditions: Environmental factors like atmospheric interference or ionospheric disturbances can introduce errors in GNSS positioning.
- Multi-path interference: Reflections or deflections of satellite signals from surfaces like buildings or mountains can cause multi-path interference, leading to inaccuracies.
- Receiver quality: The quality and sensitivity of the GNSS receiver itself can influence the accuracy of positioning.
A clear view of the sky is crucial for optimal GNSS performance. In general, GNSS receivers require a direct line of sight to multiple satellites to achieve accurate positioning. Obstructions like dense urban environments, tunnels, or dense foliage can limit satellite visibility, which can affect the accuracy and availability of GNSS positioning.
While GNSS is widely used and dependable, it does have certain limitations and challenges:
- Signal blockage: Obstructions like tall buildings, tunnels, or dense tree canopies can obstruct satellite signals, leading to degraded or no positioning information.
- Urban canyons: In dense urban environments with tall buildings, the signals are reflected, causing multi-path interference and reduced accuracy.
- Indoor positioning: GNSS signals are often too weak to penetrate buildings effectively, making it challenging to obtain accurate positioning indoors.
- Signal degradation: Environmental factors like ionospheric disturbances, solar activity, or atmospheric interference can impact the quality of GNSS signals and introduce errors in positioning.
Yes, GNSS are primarily used for navigation in remote areas and open water, provided there is a clear view of the sky. In such environments, where other navigation references are limited. GNSS can provide valuable positioning information for navigation and tracking purposes. However, it is important to consider factors like signal blockages, multipath, signal jamming and solar storms in these scenarios as well.
Geomagnetic Positioning
Geomagnetic positioning is a technique that utilizes the unique magnetic field created by the interaction of Earth’s magnetic field with structures like buildings. By surveying and referencing the magnetic anomalies, precise indoor positioning information is determined.
Geomagnetic positioning works by mapping and analyzing the magnetic anomalies caused by the presence of ferrous materials in buildings. By measuring the anomalies at various locations, a reference map is built and is used for determining the location of devices or individuals indoors.
Geomagnetic positioning offers several advantages for indoor positioning:
- Precise indoor positioning: By utilizing the unique magnetic field signatures of buildings, geomagnetic positioning can provide accurate and reliable indoor positioning information.
- Infrastructure-free: Geomagnetic positioning does not require additional infrastructure or installations since it relies on the existing magnetic fields generated by buildings.
- Cost-effective: As it utilizes existing magnetic fields, geomagnetic positioning can be a cost-effective solution for indoor positioning, particularly in environments with structures that interact significantly with Earth’s magnetic field.
Geomagnetic positioning also has certain limitations and challenges to consider:
- Magnetic field variations: Magnetic fields are influenced by factors other than the building structure, such as nearby metallic objects or electrical currents. These variations can introduce errors in positioning.
- Calibration and mapping: Creating accurate reference maps of the magnetic fields requires careful calibration and mapping processes to account for variations and changes over time.
- Limited to indoor environments: Geomagnetic positioning is used for indoor positioning as it relies on the unique magnetic fields generated by buildings. It may not be suitable for outdoor or large-scale positioning applications.
Yes, geomagnetic positioning is combined with other positioning technologies, such as inertial sensors or wireless signals, to enhance overall positioning accuracy and reliability. Integration with other technologies allows for more robust positioning solutions in complex indoor environments. Our VENUE Indoor Positioning solution leverages all these technologies in a single solution.
Geomagnetic positioning is most effective in indoor environments where buildings contain significant amounts of steel or magnetic materials. In environments with limited or weak magnetic field interactions, the effectiveness of geomagnetic positioning reduces the accuracy. Additionally, the presence of strong external magnetic sources or significant magnetic disturbances can affect the accuracy of geomagnetic positioning.
Perception Sensors
Perception sensors other than cameras are used to gather information about the surrounding environment by transmitting signals and detecting their echoes such as LiDAR and radar. They are used for detecting objects, identifying obstacles, and gathering spatial information.
Common types of perception sensors include:
- Radar: Radar sensors emit radio waves and analyze the echoes to detect the presence, distance, and speed of objects.
- Cameras: Cameras capture visual information in the form of images or video, which is processed to identify objects, patterns, and movements.
- LiDAR (Light Detection and Ranging): LiDAR sensors emit laser beams and measure the time it takes for the beams to reflect back, enabling the creation of detailed 3D maps and the detection of objects.
Perception sensors are used for obstacle avoidance and object detection. They help vehicles, robots, and other systems navigate and operate safely in their environment by identifying and responding to potential obstacles or hazards. They can also be used to map their environment by detecting fixed objects after several passes.
Yes, we leverage perception sensors for positioning purposes as well. By detecting objects and their locations in the signals’ path, perception sensors can contribute to determining the position of the sensor or the relative position of objects in the environment.
Perception sensors provide spatial information about the environment, and is adapted in positioning systems. By detecting objects and their distances away from the sensor, the position is calculated. Additionally, perception sensors can crowdsource information to create detailed maps of the environment, aiding in positioning and localization.
While perception sensors are valuable for positioning, they do have certain limitations and challenges to consider:
- Sensor limitations: Each type of perception sensor has its own limitations, such as limited range, sensitivity to weather conditions, or susceptibility to interference.
- Data processing: Perception sensor data requires processing and interpretation to extract positioning information accurately. This processing can be computationally intensive and may require advanced algorithms.
- Environmental factors: Perception sensors is such as cameras are affected by environmental conditions, such as poor visibility, adverse weather, or complex environments with reflective surfaces or occlusions.
Yes, you can integrate perception sensors with other positioning technologies, such as GNSS or inertial sensors, to enhance positioning accuracy and robustness. By combining data from multiple sensor sources, a more comprehensive and reliable positioning solution is achieved.
Speed Sensors
Speed sensors are devices or systems that measure the speed or velocity of an object or vehicle. They provide information about the rate of motion, typically in terms of distance covered per unit of time.
Speed sensors are used as inputs to derive vehicle speed, which is a critical component of velocity information in positioning systems. By measuring wheel readings or engine RPM (Revolutions Per Minute), the speed of a vehicle can be determined and utilized to enhance the accuracy of positioning information.
Common types of speed sensors include:
- Wheel speed sensors: These sensors measure the rotational speed of the vehicle’s wheels. They are used in vehicles equipped with anti-lock braking systems (ABS) or traction control systems.
- Engine speed sensors: Also known as RPM sensors, these sensors measure the rotational speed of the engine. They provide information about the engine’s speed, which calculates vehicle speed.
Speed sensors provide crucial velocity information that helps in determining the accurate position of a moving object or vehicle. By integrating speed readings over time, the calculated distance covered by the vehicle can improve the overall accuracy of the positioning system.
Speed sensors alone cannot provide absolute positioning information. They primarily contribute to velocity information, which is a vital component for accurate positioning. To determine the position accurately, speed data from sensors combined with other positioning technologies, such as GNSS or inertial sensors.
The inclusion of speed sensors in positioning systems offers many benefits, including:
- Enhanced accuracy: Speed information helps improve the accuracy of positioning calculations by providing an additional input for determining the distance traveled.
- Real-time updates: Speed sensors provide continuous updates on the vehicle’s speed, allowing for real-time adjustments in positioning calculations.
- Redundancy and reliability: Incorporating multiple sources of velocity information, including speed sensors, adds redundancy to the system and increases the overall reliability of positioning data
Limitations and considerations with speed sensors in positioning systems include:
- Calibration: Proper calibration of speed sensors is essential to ensure accurate speed readings and, consequently, accurate positioning calculations.
- Sensor accuracy: The accuracy of speed sensors can vary depending on factors such as sensor quality, environmental conditions, or vehicle-specific characteristics.
- Integration with other sensors: To achieve accurate positioning, speed sensor data integrated with other positioning technologies, such as GNSS or inertial sensors, to account for factors like acceleration, deceleration, or changes in direction.