Inclinometer Pitch and Roll Tilt Sensor ISO 2631

Yashu Systems Design Services and Core Competencies


Research and Development of Hardware / Firmware / Software for Ground Based Vehicles

• Development of Motion Control Algorithms using Closed-Loop Sensor Feedback Topologies

• Derivation of Stochastic State-Space Models : Process and Observation Definitions

• Innovation of Adaptive Stability Control Methods : Formulation, Implementation and Analysis

• Bayesian Modeling : Conception and Experimentation as applied within Sensory Networks

• ToF IR Camera Design with application to CAN-Based Anti-Collision Control

• Research of Autonomous Navigation using SLAM and Structure from Motion Techniques

• Active Suspension Control Research using Magneto-Rheological (MR) Shock Technology

Mechatronic Systems Analysis and Control Design : Custom Hardware, Firmware and Software

• Design of CAN-Based Smart Motion Sensors with Embedded Real-Time Kinematics Modeling

• Creation of MEMS-Based Devices and Formulae to Quantify Suspension Motion and Ride Comfort

• Design of All Hardware Electronics, Mechanical Enclosures and Production Test Apparatus

• Compose Software and Firmware for All Devices including Risk Management Methodologies

• Perform Patentability Studies including Prior Art Assessment of Infringement and Invalidity

Design of Wireless J1979 / J1939 / CANopen Telematics Data Loggers with Aux Sensor Support

• Extended Kalman Filter Dead Reckoning Navigation Algorithms Design (GNSS+MEMS+CAN)

• Windows Software GUI and Android / iOS BLE App Development for Data Config / Retrieval

• Logging of Isochronous Raw Data, Processed Parameters and Events with Cloud Upload Apps

Design of WiFi-Meshed Audio / Lighting Node for Passenger Service in Avionics Fuselage Cabin

• Synchronized Dimmable R/G/B/W Lighting and Voice Broadcast across all Networked Nodes

• Low-Bit-Rate Broadcast Compressed Audio using Custom SubBand ADPCM Companding

• Adaptive Periodic Noise / Echo Cancellation of Live Microphone Broadcasts across all Nodes

• Mobile Microphone Paging Feedback Suppression using UWB Real-Time Location System


Yashu Systems : Vehicle Inertia Monitor supports Automatic Terrain Identification

for the U.S. Army's Autonomous Convoy


Press Release : Yashu Systems Vehicle Inertia Monitor supports Automatic Terrain Detection System





J1939 Wireless Vehicle Health Monitor Specifications



YellowJacket Vehicle Management System Specifications


J1939 Vehicle Inertia Monitor VIM

Formulates Moving Vehicle Pitch and Roll Tilt Estimates using Multiple Sensor Fusion

J1939 Vehicle Inertial Measurement and Vibration Monitoring Device



The Vehicle Inertia Monitor is not a typical digital inclinometer that is commonplace in the J1939 market. These commodity inclinometers are intended for static environments where the vehicle is not moving and therefore generate significant pitch / roll errors when the vehicle accelerates, decelerates or turns.

The VIM incorporates advanced signal processing techniques using dynamic modeling and detected vehicle motion from the J1939 communication link. This results in extremely accurate pitch / roll estimates when the vehicle is in motion. Additionally the VIM filters noise from these attitude estimates via sensor data fusion within an Extended Kalman Filter to provide fast, smooth data results in real-time.


  New Standard Features:

High Accuracy Grms Vibration Capability with 200 microGrms Resolution

Improved Vibration Frequency Spectrum J1939 MultiPacket Transmission

Vehicle 3D Instantaneous Displacement Estimates via Extended Kalman Filter

Proprietary Stochastic State-Space Prediction + Observation Processes

 ** Now Available **

ISO 2631 Human Vibration Dosage Levels Monitoring Mode

ISO 8041 Compliant : Frequency Weightings for Wb-c-d-e-f-j-k

Real-Time Updates for Aw, RunningRMS Aw, MTVV, MSDV + VDV

Double Precision Cascaded Bi-Quad IIR Filters Implementation



VIM with 5-Pin M12 Connector and NEMA2000 Standard Pinout


Coming Soon : Pre-Production CAD Render Shown Above


Accident Detection Sensor (ADS)

ADS with 8-Pin M12 Connector (J1939 + Discrete I/O) and USB Maintenance Port


Coming Soon : Pre-Production CAD Render Shown Above



Basic Features:

DSP Microcontroller Hosts Advanced Data Processing Algorithms and Applications

J1939 CAN Bus Interface to Acquire and Transmit Vehicle Data used in Parameter Calculations

Single Low Cost Automotive Grade 6-Contact Connector for Power and CAN Bus : TriColor Status LED

Thick Walled ABS Plastic Enclosure with Brass Press Inserts : 1.9” L  x  2.3” W  x  0.56” H

-40C to +85C Wide Temperature Range Operation for Harsh Environments : Epoxy Potted : Waterproof

Core Capabilities:

Integrated MEMS Accelerometer and Gyroscope support Moving Vehicle Pitch and Roll Estimates

3-Axis Vibration Monitoring of SubBand Frequency Grms-Force Levels with Optional Order Tracking

Vehicle Attitude Monitoring Features:

Incorporates Vehicle Kinematic Model and Kalman Filtering for Real-Time Attitude Estimates

  Uses CAN Parametrics, MEMS Sensor Data and Vehicle Frame Dimensioning

  Gyroscope + Accelerometer Data Fusion via Advanced Kalman Filtering

  Performs Compensation for Vehicle Frame Longitudinal and Lateral Accelerations

  Unique Gyroscope Precession Compensation supports Vehicle Maneuvers on Inclined Surfaces

Supports Arbitrary VIM Mounting Location and Rotation when affixed to Vehicle Frame

  Integrated User-Interactive Calibration Functions simplify formulations of:

  VIM Mounting Rotation Matrix using Yaw, Pitch and Roll

  Vehicle Drive Wheel Speeds Difference Correction Factor

Vibration and Health Monitoring Features:

3-Axis Selectable Sensitivity / Bandwidth Vibration Monitoring Device with J1939 Interface

  Selectable AC / DC Coupling with Full Scale Vibration Ranges of:

  ± 2G max  or  ± 6G max  @  200uGrms SubBand Grms Value Quantization

  < 4mGrms typ noise level @ 2Khz BW (Post FFT-Based Parseval’s Theorem Processing)

  < 1mGrms typ noise level @ < 300Hz BW (Post FFT-Based Parseval’s Theorem Processing)

  45dB Typ Instantaneous Dynamic Range with Configurable Bandwidth / Resolution of:

BW (Hz)

Res (Hz)

BW (Hz)

Res (Hz)













Real-Time Grms Level Monitoring within Configurable Frequency SubBands

  SubBand Frequency Order Tracking to a Configurable J1939 Sync Parameter

Real-Time Spectrum Display w/ Peak Hold and Logarithmic Display Options

  Fast Update Rate across J1939 using P2P MultiPacket Messaging

  FFT Spectral Overlapping at 25ms Frame Rate results in No Missed Data

Advanced Spectral or Cepstral Domain Based Gearbox Analyses and Profiling (Future)

  Multipacket P2P or BAM Transmission of Matrix Data at Configurable J1939 Rate

  Spectrum / Cepstrum Order Tracking Support to a Configurable J1939 Sync Parameter

  Optional Bispectrum Based Analysis Mode combats High Noise Environments

  Supports transmission of Full 3D Bispectrum or Diagonal Slice Vector

  Selectable FFT Size, Window Type, Max Lag Vector and Biased / Unbiased Estimate

Configuration, Monitoring and Maintenance Device Utility Software:

User Friendly Utility Software to Configure and Monitor VIM while Installed to Target Vehicle

  Monitor Vehicle Attitude and Vibration Levels : Real-Time Spectrum Analyzer Window Display

  Perform VIM Non-Volatile Configurations for Operating Mode with Associated Parameters


VIM Arbitrary Mounting Position

VIM Arbitrary Mounting Rotation w/ AutoCal


VIM Operating Mode and Settings

Vehicle Wheel Speeds L/R Ratio w/ AutoCal



VIM Vibration Mode Parameters


VIM Vibration Mode SubBand Configuration


VIM Attitude Mode Parameters



VIM Specifications Sheet: VIM Specifications Sheet (.pdf)

VIM Stability Control App Video: VIM SCS Application Example (YouTube)


The Following Video Shows Real-Time VIM Pitch / Roll Estimates during Vehicle Maneuvers

VIM Vehicle Pitch / Roll Video: VIM Attitude Estimates Example (.wmv)

  Real-Time Attitude Estimates of Vehicle doing Qty-2 Figure-8 Patterns on Smooth 6-Degree Ramp

  Thin Dashed Trace shows Noisy Accelerometer-Based-Only Estimates

  Vehicle Frame Acceleration Compensation is Included within Accel-Only Estimates

  Thick Solid Trace Fuses Precession-Compensated Gyroscope Data to the Accel-Only Estimates


The Following Videos Show the Weaknesses and Inaccuracies of Competing J1939 Inclinometers

Vehicle Pitch / Roll Video without Vehicle Frame Acceleration Compensation:

Typical Digital Inclinometer Attitude Estimates Example (.wmv)

  Video Shows Erroneous Results from a Typical Competing J1939 Digital Inclinometer

  Roll Estimates are Permuted due to Lateral Acceleration during Turns at Top / Bottom of Ramp

Ø  VIM Solves this issue using Dynamic Kinematic Modeling and Detected Motion of the Vehicle


VIM Vehicle Pitch / Roll Video without Gyro Precession Compensation:

VIM Attitude Estimates without Gyro Precession Comp Example (.wmv)

  Video Shows Kalman Estimate Overshoot resulting from Gyro Bleed between Pitch and Roll Axes

  Prominent Overshoot Occurs in Pitch Estimate during Right Turn-Around at Top of Ramp

Ø  VIM Solves this issue using a 2D Plane Based Reference to Minimize Precession Bleed


VIM Vibration GUI Screen Shot: Swept Sine Wave on Small Speaker Diaphragm

VIM Evaluation Software : Real-Time Spectrum and Vibration GUI


J1939 USB CAN Interface UCI1





Establishes In-Vehicle Link between Device Utility Software and Vehicle-Installed VIM Unit(s)

Used to Perform In-Vehicle VIM Configuration, Real-Time Data Inspection and Firmware Upgrades

Standard 9-Pin J1939 Deutsch Locking Connector : PC Host and J1939 Bus TriColor Status LEDs

Galvanically Isolated USB 2.0 Interface with Standard Mini-B Connector


J1939 Miniature Data Logger MDL1




Pre-Production Prototype Shown Above


Conforms to SAE J1939 Protocol and Mates to Vehicle’s OnBoard Diagnostic Data Connector

Supports Configurable Custom SPNs Logging Scripts including DTCs and Component IDs

  Provides Capability for Multiple Simultaneous Logging Profiles and Sampling Rates

Intuitive Data Extraction Software supports Uploading, Previewing and Saving of Logged Information

Realtime Clock with Rechargeable Battery Backup maintains Accurate Time when removed from Vehicle

Low Power Sleep Mode allows Permanent Installation to Vehicle with WakeUp on Specific CAN Activity

  Integrated MEMS Accelerometer and Gyroscope also allows WakeUp on Motion Detect

Computes and Logs Moving Vehicle Pitch / Roll Estimates with Compensation for Frame Accelerations

  Incorporates Advanced Vehicle Kinematic Model allowing for Arbitrary Mounting Location of MDL

Integrated Backup Power Supply provides Immunity to Surprise Loss of Vehicle Power and Brownouts

USB 2.0 Interface using Standard Mini-B Connector : Small Rugged Enclosure with Gold Plated Contacts

Standard 9-Pin J1939 Deutsch Locking Connector : PC Host and J1939 Bus TriColor Status LEDs



J1939 Miniature Data Logger Software : Custom SPNs Data Logging GUI



J1939 Miniature Data Logger Software : Data Retrieve and Settings GUIs




ZigBee DSP Inertia Monitor DIM1 + Remote Sensor Monitor RSM1

- Developed by Yashu Systems for Boeing Aircraft -

- Advanced Rotorcraft Technology -

Boeing Adaptive Vehicle Management System - Streaming Video (YouTube)




DSP Inertia Monitor v1




Remote Sensor Monitor v1


DIM1 Features:

Supports TC / RTD, Pressure, Flow, Strain, Proximity, 4-20mA, Analog and ICP Accelerometer Sensors

Integrated 6-DOF Inertial Measurement Unit : Extended Kalman Filter provides Pitch / Roll Estimates

2 Configurable Input Channels based on Wheatstone Bridge : 2 ICP Accelerometer Channels

Universal Sensor Input Channel Design supports Almost Any Sensor Type

Robust Bridge Interface Allows for Quarter, Half or Full Bridge Configurations

Isolated Programmable Constant Current Source Excitation for Each Sensor Channel

Deep Sleep Capability with Motion Sensing Wakeup : Qty 4 AA NiMH Batteries Drawer


RSM1 Features:

Provides Wireless Interfacing from DIM1 to a Remote Sensor : Support for Various Sensor Types

Programmable Gain Inst Amplifier : Floating Differential Inputs : High Capacity 2/3A Lithium Battery

Integrated 3-Axis MEMS Accelerometer : Deep Sleep Capability with Motion Sensing Wakeup

Provides Programmable Constant Current Sensor Excitation for Immunity to Sensor Cable IR Losses

High Grade Aluminum Enclosure : Waterproof / Shockproof : -40C to +85C Temperature Range

Operates in Extreme Environments : Up to +/- 50G Continuous Acceleration Force along any Axis


ZigBee DSP Sensor Module DSM1 : 802.15.4 Wireless Universal Sensor Interface Module

- Developed by Yashu Systems for BAE Systems -

Supports TC / RTD, Pressure, Flow, Strain, Proximity, 4-20mA, Analog and ICP Accelerometer Sensors

4 Configurable Input Channels based on Wheatstone Bridge : 2 ICP Accelerometer Channels

Universal Sensor Input Channel Design supports Almost Any Sensor Type

Robust Bridge Interface Allows for Quarter, Half or Full Bridge Configurations

Isolated Programmable Constant Current Source Excitation for Each Sensor Channel



1Hz to 5KHz BW Accelerometer Channels with Programmable AntiAlias LowPass Filter Cutoff

24VDC @ 4mA Constant Current ICP Accelerometer Excitation Support

Programmable Gain Amplifiers on All Sensor and ICP Accelerometer Channels

HiSide Power Switches for Channel Banks allow Robust Sleep Modes to conserve Battery Life

40MHz 16-Bit Fixed Point DSP with 2 MByte SRAM

USB 2.0 Full Speed Host Interface for Maintenance and Configuration

Logs Sensor Data using Per Channel User Specifiable Rates

Dual 3.6V D-Cell Lithium Batteries provide Months of DSP Processed Data Logging Operation

-40C to +85C Wide Temperature Range Operation for Harsh Environments

Rugged Urethane Boot Cover provides High Water Resistance

Extruded Aluminum Base provides Secure Vehicle Attachment

Sensor Cables feed through Cable Channels to Screw Terminals under Protective Boot

10-32 Coax ICP Accelerometer Connectors provide Extremely Low Noise Interfacing


DSM1 Unique Functionality

• Independent Channels allow configuring 4 Different Sensor Types on a single DSM1 Unit

• Floating Differential Input Channels provide Isolation and High CMRR for Attached Sensors

• 7-Screw Terminal Channel Connector leverages attachment of Various Sensor Types

• Selectable Ranges for TCs provide Cold Junction Compensated Hi-Resolution Dynamic Ranging

• Selectable Ranges for ICP Accel, RTD, Strain and Analog Voltage Sensors increases Readout Resolution

• Optional API Development Library allows user to create Custom DSP Firmware Algorithms

• Optional Auxiliary I2C Port allows connection of Application Specific Smart Sensors


DSM Specifications Sheet: DSM1 Specifications Sheet v4 (.pdf)

API Script Library Functions: DSM1 Script Library Functions (.pdf)

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